See Gigabit Ethernet.
See Fast Ethernet.
In reference to the Windows operating systems, one that can utilize up to 4 GB of address space. (5)
In reference to the Windows operating systems, one that can utilize more than 4 GB of address space. Depending on the version, 64-bit Windows can address a maximum of from 8 to 192 GB. (5)
A wireless network standard that uses the 5 GHz band. (13)
A wireless network standard that uses the 2.4 GHz band at a speed of up to 10 Mbps. (13)
A wireless network standard that uses the 2.4 GHz band at a speed of up to 54 Mbps. It is downward-compatible with 802.11b. (13)
A wireless network standard that defines speeds of up to 600 Mbps. It is downward-compatible with 802.11a, 802.11b, and 802.11g. (13)
8-bit high color
Describes the VGA mode color setting that, although it can produce around 16 million different colors, can only display up to 256 different colors at a time. (3)
See alternating current.
A type of power supply that converts AC power to voltages needed for a device. AC adapters are generally used for portable PC systems and other devices. (6)
accelerated graphics port (AGP)
A local bus designed for video only, it provides a direct link between the processor and the video card, giving the video card direct access to main memory. (1)
Managing access to resources. Access control to computers and network resources involves authentication and authorization. (16)
access control entry (ACE)
In an access control list, a record containing just one user or group account name and the permissions assigned to that account. (16)
access control list (ACL)
A table on each file and folder in the NTFS file system that contains one or more access control entries. (16)
In a laptop, a compartment that holds a single media device that is switchable with another. (6)
See access control entry.
See access control list.
See Advanced Configuration and Power Interface.
See Advanced Communications Riser.
The "activity" status light on a NIC that indicates data is being transmitted. (5)
A method used by several software manufacturers to combat software piracy. The formal name for Microsoft's activation is Microsoft Product Activation (MPA). (9)
A set of behaviors including active listening and active speaking that shows you are fully engaged in the conversation and encourages the other person to also communicate in a positive manner. (18)
active KVM switch
See electronic KVM switch.
A set of skills, behaviors, and attitudes to use when listening to another person. (18)
active matrix display
An LCD technology based on thin-film transistor (TFT) technology. An active matrix display has a transistor at every pixel, which enables much quicker display changes than passive matrix displays and produces a display quality comparable to a CRT. (3)
A primary partition that is marked for use by the system during startup. Windows operating systems can only be booted from an active partition. (10)
The appropriate responses that you make during a conversation. (18)
ad hoc mode
In a Wi-Fi network, the networking mode that allows peer-to-peer communications without the use of a centralized wireless hub, called a wireless access point (WAP). (14)
A printed circuit card that you add to the motherboard to enhance functionality. Also called an expansion card. Video adapters and network interface cards (NICs) are examples of adapter cards. (2)
A group of wires used to identify addresses in main system memory in a computer. The number of wires in an address bus is called the width of the bus and determines the number of unique memory locations that can be addressed using binary math with the two raised to the power of the number of wires in the bus. A 32-bit bus can address up to 4 GB of memory, whereas a 36-bit address bus can address up to 64 GB of memory. (1)
Address Resolution Protocol (ARP)
A protocol used to resolve an IP address to a MAC address. (13)
Advanced Communications Riser (ACR)
A riser card standard that AMD, 3Com, and others introduced in 2000 to supersede AMR. It uses one PCI slot, provides accelerated audio and modem functions as well as networking, and supports multiple Ethernet NICs. (2)
Advanced Configuration and Power Interface (ACPI)
A power management standard that includes all the power states of APM, plus two more. It also supports soft power. (6)
Advanced Micro Devices (AMD)
AMD manufactures CPUs and other products, and its chief rival is Intel Corporation. (1)
Advanced Power Management (APM)
A power management standard, introduced by Intel in 1992, that defines four power-usage operating levels. (6)
Advanced Technology (AT)
A type of motherboard used in older PC systems; also refers to the 1984 IBM PC AT model. (1)
Advanced Technology Attachment (ATA)
The former name of the Parallel AT Attachment (PATA) interface standard. (1)
Advanced Technology eXtended (ATX)
A type of motherboard and its variants most commonly used in recent PC systems. (1)
Software installed on a computer without permission that collects information about a user in order to display targeted advertisements, in the form of either inline banners or pop-ups. Inline banners are advertisements that run within the context of the current page, taking up screen real estate. (16)
See accelerated graphics port.
The delivery of electricity (as from a wall outlet) in which the flow of electrons reverses periodically and has alternating positive and negative values. (3)
See arithmetic logic unit.
See Advanced Micro Devices.
American National Standards Institute (ANSI)
A technical standards organization. (3)
A measurement of the volume of electrons, also called current. It is calculated with the formula amps = watts / volts. (3)
See audio modem riser.
analog LCD display
An LCD display that uses a DB-15 connector, which means that it accepts analog signals that it converts to digital. (3)
A modulator/demodulator device that allows computers to communicate with one another over existing phone lines. (2)
See American National Standards Institute.
A file used during an unattended installation of Windows. It provides a script of responses to the questions Setup asks so the user does not have to answer them manually. (9)
A mat that provides a path to ground for a static charge and is designed for the desktop or floor of a workspace. One placed on the workbench reduces the risk of electrostatic discharge for components placed on it, while one placed on the floor provides the same protection for anyone standing on the mat. (5)
antistatic wrist strap
A strap designed to discharge static electricity from your body. One end attaches to the wrist, whereas the other end attaches to a grounded object. (5)
See Automatic Private IP Address.
See Advanced Power Management.
A file attribute set by the OS when a file is created or modified. Backup software often removes this attribute when backing up a file in order to mark it as a backed-up file. (10)
arithmetic logic unit (ALU)
A component of a CPU that is responsible for all logical and mathematical operations in the system. (1)
See Address Resolution Protocol.
The proportion between an image's width and height. Traditional CRT monitors have an aspect ratio of 4:3. Widescreen displays have an aspect ratio of 16:9. (3)
See automated system recovery.
asymmetrical digital subscriber line (ADSL)
A type of DSL service in which the download speed is higher than the upload speed. (13)
asynchronous transfer mode (ATM)
A type of switched network used by phone companies. (13)
See Advanced Technology.
See Advanced Technology Attachment.
ATA Packet Interface (ATAPI)
The protocol for connecting optical drives and tape drives to an ATA channel. (1)
See ATA Packet Interface.
See asynchronous transfer mode.
An installation of Windows that is not automated, where the user is required to pay attention throughout the entire process to provide information and to respond to messages. Also called a manual installation. (9)
A power supply standard that has both the 20-pin connector for the motherboard and a 4-pin 12 V connector. (3)
See Advanced Technology eXtended.
ATX power supply
A power supply form factor that pairs with an ATX motherboard and case. (3)
audio modem riser (AMR)
A small expansion card introduced in the late 1990s that plugs into a special slot on a motherboard and uses the CPU to perform modem functions and sound functions. It is not plug and play compatible. (2)
In Windows, one or more settings found in the Local Security Settings console. (16)
See security auditing.
Authentication is validation of a user account and password that occurs before the security components of Windows will give the user access to the computer. (16)
Things used for authentication, such as something you know, something you have, or something you are. Authentication involves one or more of these factors and can, therefore, be one-factor, two-factor, or three-factor authentication. (16)
The process that authenticates a user and verifies the user account's level of access to a resource. (16)
Automated System Recovery (ASR)
An option available in the Windows XP Backup program for recovering from damage that prevents the operating system from starting. It replaced the Emergency Repair Disk (ERD) process in Windows 2000. (11)
Automated System Recovery (ASR)
In Windows XP, this replaces the Emergency Repair process of Windows NT and Windows 2000. ASR is available from the Windows Backup program (NTBACKUP.EXE). (11)
Automatic Private IP Address (APIPA)
An address that a DHCP client will assign to itself after requesting an address and failing to receive one from a DHCP server. The address it will assign is in the 169.254 /16 network, which is the range of addresses from 169.254.0.1 to 169.254.255.254. (13)
auto-switching power supply
A power supply that detects the incoming voltage and switches to accept either 120 or 240 VAC. (6)
Program code that provides a way for someone to gain access to a computer while bypassing security. Only a person who knows how the back door works can use it, but once in, that individual has the same access as the host program to all the internal operating system code. (16)
A process that runs "behind the scenes" with a low priority, does not require input, and rarely creates output. (11)
Any writable mass storage device, removable or fixed in place. (2)
Balanced Technology eXtended
A motherboard form factor introduced in 2003 by Intel as the successor to ATX. (1)
The amount of data that can travel over a network at a given time. (13)
bar code reader
A specialized type of scanner that reads bar codes, which are patterns of bars of varying widths printed on labels or directly on items. The bar pattern is converted into a numeric code that is transmitted to a computer as data. (3)
base priority level
See process priority level.
A disk that uses basic storage, which means that it uses the partition table in the master boot record (MBR) to define disk partitions. (10)
basic input/output system (BIOS)
A type of computer firmware that is responsible for informing the CPU of installed devices and how to communicate with them. (1)
Basic Service Set (BSS)
The wireless nodes (including the WAP) communicating together in infrastructure mode. (14)
A storage type in Windows that uses the partition table in the master boot record (MBR) to define disk partitions. (10)
A tool used to create and manage a distribution share and various installation images. (9)
The type of connector used in the ExpressCard interface. (6)
A parallel port mode in which the signals can be transmitted in both directions between the PC and parallel devices connected to the computer. (4)
A measurement of a body part, such as a fingerprint or retina scan. (16)
A device that uses a measurement of a body part, such as a fingerprint or retina scan. (3)
The use of a biometric for authentication. (16)
See basic input/output system.
The BIOS configuration settings, also called system settings, accessed via a special BIOS-based menu during system startup. (4)
In reference to a memory module, how much information the processor can access from or write to memory in a single cycle. (2)
BitLocker drive encryption
An encryption technology introduced in Windows Vista Enterprise and Ultimate editions, Windows Server 2008, and also in Windows 7 Ultimate and Enterprise editions. It encrypts the entire boot volume. (16)
The act of covertly obtaining information broadcast from wireless devices using the Bluetooth standard. (16)
A wireless standard for using radio waves to communicate between devices. Class 3 Bluetooth devices (the most common) communicate at distances up to one meter. (6)
The high-definition optical disc formatting standard developed by the Blu-ray Disc Association whose members include Sony, 20th Century Fox, Dell, Hewlett-Packard, and many other industry leaders. (2)
A connector used to attach coaxial cables to computers and network equipment. Origin of the term may be "Bayonet-Neill-Concelman" or "British Naval Connector." (2)
The first physical sector on a floppy disk or the first sector on a hard drive partition. The boot record contains information about the OS. The boot record on a primary active partition is used to start the operating system. Also called the boot sector. Do not confuse this with the master boot record. (10)
See boot record.
The order in which the BIOS will search devices for an operating system to start. (4)
A network connection device that passes traffic between two networks, using the physical address (MAC address) of the destination device. (13)
A wide area network (WAN) connection that allows a large amount of data to be transmitted. Broadband WANs includes cellular, ISDN, DSL, cable, T-carrier, satellite, and fiber. (13)
See Balanced Technology eXtended.
A popular inkjet printer developed by Canon. (12)
In a computer, pathways that power, data, and control signals travel from one component to another within the system. (2)
Used to represent the chrominance signal in S-Video. (3)
An EIDE drive setting that has the system select the drive's role (master or slave) based on the drive's position on the cable. If the drive is on the end of the cable, it is the master drive, and if it is in the middle of the cable, it is the slave drive. (4)
A tool for testing if a cable can connect properly end-to-end and to determine if a cable has a short. These tools are available for a variety of cable types. (5)
A CPU component that manages the CPU cache. (1)
In power supplies, the amount of wattage the power supply can handle. (3)
A category of adapter card that accepts and records video signals to a PC's hard drive. A TV tuner card is a type of capture card. (2)
A service on a laptop that configures a card after socket services has recognized it. (6)
The PCMCIA standard that succeeds the PC Card. (6)
The box that houses the main computer system. (1)
A cooling fan mounted directly on the case, as opposed to a power supply fan, which is inside the power supply. (3)
cathode ray tube (CRT) monitor
A display device that contains a cathode ray tube and uses an electron gun to activate phosphors behind the screen at the front of the tub. (3)
See compact disc.
A drive that can write once to a special CD-R disc. (1)
See Compact Disc-Read-Only Memory.
A drive on a computer that can play music CDs and read data CDs, but cannot write to CDs. (1)
A drive that can write either to CD-R discs or to specially designed CD-RW discs. In the case of the CD-RW discs, the drive can write more than once to the same portion of disc, overwriting old data. (1)
Data communications over the cellular telecommunications networks. (6)
central processing unit (CPU)
The primary control device for a computer system. The CPU is simply a chip containing a set of components that manages all the activities. Also called a processor. (1)
A 36-pin connector mounted to a device's parallel interface. (3)
channel service unit (CSU)
A device required at both ends of a T-carrier system connection. (13)
In the laser printing process, the stage in which the printer's high-voltage power supply (HVPS) conducts electricity to the primary corona wire so it can pass the voltage on to the printer's electro-photosensitive drum. (12)
One or more chips designed to work closely with the CPU. Two parts of this chipset are the Northbridge and the Southbridge. (1)
The signal in a television transmission that contains the color of the image. (3)
In the laser printing process, the stage in which the image is removed from the photosensitive drum so it can accept the next image. (12)
In the laser printing process, a blade that removes residual toner from the drum. (12)
A network in which dedicated computers called servers store data and provide print services or other capabilities to computers running the appropriate client service or services. (13)
In a CPU, the speed at which it can potentially execute instructions, measured in millions of cycles per second—megahertz (MHz)—or billions of cycles per second—gigahertz (GHz). (1)
The minimum disk space that a file can use, allocated in the file system. (10)
See complementary metal-oxide semiconductor.
A misnomer, referring to the BIOS settings that are stored in a CMOS chip. (1)
See communication network riser.
Cabling that contains a single copper wire surrounded by several layers of insulating plastic and a woven wire sheath that provides protection. (3)
Code Division Multiple Access (CDMA)
The cellular network standards used by Verizon and Sprint-Nextel. (13)
A practice begun in Windows 2000 in which all of the operating system code is digitally signed to show that it has not been tampered with. (9)
The number of colors used by a display. (3)
A Windows display setting that allows you to adjust the number of colors, or color depth, used by the display. (3)
communication network riser (CNR)
A riser card that is similar to audio modem riser (AMR) except that it is plug and play-compatible and supports LANs in addition to audio, modem, and sound. (2)
compact disc (CD)
An optical disc created and read by a mechanism using a laser. (2)
Compact Disc File System (CDFS)
A file system used by operating systems for organizing, reading, and writing optical discs. (10)
Compact Disc-Read-Only Memory (CD-ROM)
Laser discs sold at retail stores that contain music (audio CDs) or software (data CDs). (1)
A type of solid-state storage that is commonly used in a variety of devices, such as digital cameras. (2)
complementary metal-oxide semiconductor (CMOS)
A chip that retains system settings such as the time, keyboard settings, and boot sequence. (1)
A video signaling method in which analog video information is transmitted as two or more discrete signals. Two general types of component video are RGB Video and S-Video. (3)
The traditional transmission system for television video signals, which combines the color and brightness information with the synchronization data into one signal. The TV circuitry then separates the two signals from the composite signal. (3)
The hardware architecture, including the CPU, BIOS, and chipset. (8)
A generic reference to a PC's serial communications port, in which the x represents the port number. (5)
The plug at the end of a cable or the port or connection point on a computer or device. (3)
continuity RIMM (CRIMM)
A special terminating stick that must be inserted into the open RIMM sockets. (4)
The difference in value between a display's brightest white and darkest black. Modern LCD displays have a contrast ratio of 500:1 or greater. (3)
A Windows folder that contains numerous applets you can use to adjust the configuration of many different aspects of the OS. (8)
In a CPU, the component that is primarily responsible for directing all the activities of the computer and the interactions of its components. (1)
Small text files a Web browser saves on the local hard drive at the request of a Website. Cookies can contain information that will be used the next time the user connects to the Website. (16)
A file operation in which the file or folder remains in the source location, and a duplicate is created in the target (destination) location. (10)
See customer premises equipment.
See central processing unit.
A cooling fan located on a CPU. (3)
See continuity RIMM.
A multi-GPU solution developed by ATI. (3)
See cathode ray tube (CRT) monitor.
See channel service unit.
customer premises equipment (CPE)
A T-1 multiplexer or a special LAN bridge that connects to the telephone company's channel service unit (CSU), which encodes data for transmission over a T-carrier circuit. (13)
The moving of data from one storage device to another. (9)
The chunks into which the TCP protocol packages data. In addition to the data, each datagram contains information, stored in a header, which is used by the TCP protocol on the receiving end to reassemble the chunks of data into the original message. (13)
A type of riser card that connects directly into a motherboard and adds no additional functionality of its own, but extends the expansion bus and allows expansion cards to be added in a different physical orientation. (2)
A 25-pin D-shell connector. (3)
A 9-pin D-shell connector. (3)
See direct current.
A device found in laptops that monitors and regulates power usage. The features vary by manufacturer, but typically, they provide short-circuit protection, give "low battery" warnings, and can be configured to shut down the computer automatically when the power is low. (6)
See distributed denial of service attack.
See double-data rate (DDR) SDRAM.
See double-data rate (DDR) SDRAM.
See double-data rate (DDR) SDRAM.
See double-data rate (DDR) SDRAM.
See DDR2 SDRAM.
A RAM standard that replaces the original DDR standard. Using far less power than DDR1, a stick of DDR2 SDRAM has 240 pins. (2)
See DDR3 SDRAM.
A RAM standard that replaces the original DDR2 standard and requires far less power, while providing almost twice the bandwidth. A stick of DDR3 SDRAM has 240 pins, but is keyed so it will not fit into a socket designed for DDR2. DDR3 SO-DIMMs have 204 pins. (2)
A dark spot on an LCD screen caused when a transistor is permanently off. (7)
A Windows Advanced Options menu choice used to send debugging information about the Windows startup over a serial cable to another computer running a special program called a debugger. (11)
In an IP configuration, the address of the local router that acts as a gateway from the local network to other IP networks. (13)
The process of using an oscillating magnetic field to reduce and randomize the magnetic field that builds up on the shadow mask of a CRT monitor. (3)
demilitarized zone (DMZ)
In computer networking, a network located between a private network and the Internet with a firewall on both sides. A DMZ contains servers offering services to users on the Internet and inside the protected private network. (16)
denial of service (DoS) attack
This attack occurs when someone sends a large number of requests to a server, overwhelming the server so it stops functioning on the network. (16)
In the laser printing process, this is the step in which the cover on the printer's toner cartridge is opened and the toner particles are attracted to the relatively less negatively charged areas of the drum. (12)
Program code that allows an operating system to control the use of a physical device. (9)
A Windows GUI utility that allows an administrator to view the status of devices and install, remove, and update device drivers. (8)
See Dynamic Host Configuration Protocol.
A server running the Dynamic Host Configuration Protocol (DHCP) service. This server allocates IP addresses to DHCP client computers. (13)
A program that causes a modem to dial phone numbers surreptitiously. (16)
A WAN connection that uses an analog modem rather than a network card and uses standard phone cables rather than network cables. (13)
See analog modem.
digital LCD display
An LCD display that accepts a digital signal. Early LCD displays accepted an analog signal and converted it to digital internally. (3)
Digital Light Processing (DLP)
An optical semiconductor used in small projectors and in rear-projection televisions. (3)
digital linear tape (DLT)
A technology developed in the 1980s for storing data. Variations of this format are in use today. (2)
Encrypted data placed in a file to guard against tampering. (9)
digital subscriber line (DSL)
A WAN connection that uses existing copper telephone wire for the communication circuit. To accomplish this, a DSL modem splits the existing phone line into two bands; voice transmission uses the frequencies below 4000 Hz, whereas data transmission uses everything else. (13)
digital versatile disc (DVD)
A disc designed to store all types of data usable by a computer. This term also refers to the drives that read and write to these discs. There are various types of DVD drives and media. (1)
digital video discs
The original digital discs created in 1995 for storing video. (1)
digital video interface (DVI)
A digital video interface that has several modes, including one that offers downward compatibility with analog displays. It requires a special connector, which comes in several variations to support the DVI modes. (3)
digital video recorder (DVR)
A device that records video content to disk. (4)
See digitizing tablet.
An input device that uses a stylus. Available as an external device, it uses touch screen technology and is usually at least the size of a sheet of paper. Also called a digitizer. (6)
See dual inline memory module (DIMM).
A round connector that gets its name from Deutsche Industrie Norm, a German standards organization. Normally a round connector with a circular or semicircle of pins. (3)
Dual inline package. A very tiny slide that indicates two states. Motherboard and other circuit cards often have one or more groupings of DIP switches for configuring options. (4)
direct current (DC)
The type of electrical current delivered by a battery in which the electrons flow in only one direction. (3)
direct memory access (DMA) channel
A system resource that certain devices, such as sound cards and hard drives, can use to move data between the device and system RAM without involving the processor. (5)
direct thermal printer
A type of thermal printer in which a heated print head burns dots into the surface of heat-sensitive paper. (12)
Directory Services Restore Mode
In Windows, an Advanced Option that is only available in Windows Servers in the role of domain controllers, although it appears on the menu in non-domain controllers. (11)
Disable Automatic Restart
An Advanced Options choice that will temporarily disable the Automatically Restart option on the Advanced page of System Properties. (11)
Not revealing information about someone that would be harmful to or embarrass him or her. (18)
A screen device for video output. Also called a monitor. (3)
Display Brightness Key
A key on a laptop that, when pressed along with the FN key, changes the laptop display brightness at the hardware level. On some laptops, when this key combination is pressed, a small brightness control panel will display on the screen. Use the up (↑) or right (→) arrow key to increase the brightness, and use the left (←) or down (↓) arrow key to decrease the brightness. The DISPLAY BRIGHTNESS key is normally a function key, such as F5, that displays a sun-like symbol. (6)
Display Mode Key
A key on a laptop that is pressed along with the FN key to change display modes so the output will be only to the laptop's display, only to an external display, or simultaneously to both displays. The DISPLAY MODE key is normally a function key, such as F7, that displays a display symbol. (6)
display power-management signaling (DPMS)
A VESA standard for power management in display devices. (3)
The displayable number of pixels, expressed as x and y numbers, such as 1024 × 768, 1152 × 864, and 1280 × 1024. (3)
A digital display interface standard developed by the Video Electronics Standards Association that supports both video and audio signals, contains HDCP copy protection, and is unique because it is royalty-free to manufacturers. (3)
distributed denial of service (DDoS) attack
This attack occurs when a massive number (up to hundreds of thousands) of computers send DoS attacks to a server, making it unavailable. (16)
Distributed File System (DFS)
A service implemented on Windows Servers that hides the complexity of the network from end users in that it makes files that are distributed across multiple servers appear as if they are in one place. (10)
A server containing source files for installing software onto client computers. The shared folder containing these files is a software distribution point. (9)
A shared folder on a distribution server containing the source files for a remote installation. (9)
See Digital Light Processing.
See digital linear tape.
A specialized chip that controls DMA channels. (5)
See demilitarized zone.
See Domain Name Service.
A server that manages DNS names. (13)
A more advanced and more expensive alternative to a port replicator. In addition to the ports normally found on a port replicator, a docking station may include full-size expansion slots and drives. (6)
In a Microsoft Windows network, an administrative organization with a centralized security accounts database maintained on one or more special servers called domain controllers. This centralized database contains accounts for users, groups, and computers participating in the domain, and it is used to authenticate a user for access to any resource in the domain. (13)
Domain Name Service (DNS)
The Internet service that manages access to Internet domain names and the naming system it uses for computers and resources connected to the Internet or in a private network. (13)
See denial of service (DoS) attack.
dot matrix printer
A type of printer that uses a matrix of pins striking paper through an ink ribbon to create dots on the paper, forming alphanumeric characters and graphic images. (12)
dotted decimal notation
The format in which IP addresses are usually shown, with decimal numbers separated by "dots" as in 192.168.100.2. (13)
double-data rate (DDR) SDRAM
RAM that doubles the rate of speed at which a standard SDRAM can process data. Also called DDR and DDR1. A stick of DDR1 SDRAM has 184 pins. (2)
double-sided (DS) DVD
A DVD of any type that can store data on both sides of the disc. (1)
See display power-management signaling.
See dynamic RAM.
An exact duplicate of an entire hard drive's contents, including the OS and all installed software. (9)
drive lock password
A password that locks your hard drive and is often stored in a TPM chip. (16)
When a mount point exists between a partition or volume to a folder on another volume, the drive path is the path (including a drive letter) to that partition or volume. (10)
A program downloaded to a computer without the user's consent. The user unwittingly initiates the download by some simple act, such as browsing to a Website or opening an e-mail message written in HTML. Or a user may initiate a drive-by download by installing an application. (16)
The practice of applying a digital signature to device driver code. (9)
See digital subscriber line.
dual inline memory module (DIMM)
A memory module (stick) that installs into matching DIMM sockets found on many motherboards. The word "dual" refers to the separate pins or connections on both sides of the module and socket. (1)
dual layer (DL)
Pertaining to a DVD drive and disc that can store data in two pitted layers on each data side, with each layer having a different reflectivity index. (1)
A CPU containing two CPU cores. (1)
See digital versatile disc (DVD).
Digital versatile disc (DVD) discs that can be written to, but data cannot be overwritten. This standard is newer than DVD-R. This term also refers to the drives that can write to these discs. (2)
Digital versatile disc (DVD) discs that can be rewritten to, and data can also be overwritten. This standard is newer than DVD-RW. This term also refers to the drives that can write to these discs. (2)
A double-sided, single-layer digital versatile disc (DVD) that stores 9.4 GB of data, or over four hours of video. (2)
A double-sided, double-layer digital versatile disc (DVD) that stores 17.08 GB of data, or over eight hours of video. (2)
A single-sided, single-layer digital versatile disc (DVD) that stores 4.7 GB of data, or over two hours of video. (2)
A single-sided, double-layer digital versatile disc (DVD) that stores 8.54 GB of data, or over four hours of video. (2)
A blanket term used for DVD discs regardless of the type of data they contain. (2)
Digital versatile disc (DVD) discs that can be written to once, but data cannot be overwritten. This term also refers to the drives that can write to these discs. (2)
The digital versatile disc (DVD) encoding format used for data storage. (2)
The read-only DVD discs sold at retail stores, containing video or software and having a maximum capacity of 15.9 GB of data. This term also applies to the drives that can only read DVDs. (2)
A DVD drive that cannot write to but can read DVD discs. (2)
Digital versatile disc (DVD) discs that can be written to, and data can also be overwritten. This term also refers to the drives that can write to these discs. (2)
The original digital versatile disc (DVD) encoding format used for movies sold at retail. (2)
See digital video interface.
A DVI mode that supports downward compatibility with analog displays. (3)
A DVI mode that supports digital video signals and is partially compatible with HDMI. See also digital video interface and High-Definition Multimedia Interface. (3)
A DVI mode that supports both analog and digital video signals. (3)
Windows run-line utility for testing the DirectX support. Launch this program when experiencing video problems and/or audio problems when running DirectX applications. (11)
A disk type introduced with Windows 2000 that contains space allocated in volumes without the limits imposed on basic disks. On a dynamic disk, the number of volumes are unlimited, and a volume can extend to include available space on any hard disk in the computer. (10)
Dynamic Host Configuration Protocol (DHCP)
The protocol used by DHCP servers and clients. A DHCP server allocates IP addresses within the scope of addresses configured on the server by an administrator. DHCP clients request IP addresses and other IP configuration settings from DHCP Servers. (13)
dynamic RAM (DRAM)
Memory chips that provide much slower access than SRAM chips but that can store several megabytes of data on a single chip (or hundreds of megabytes, or even gigabytes, when they are packaged together on a "stick"). (2)
A method for allocating disk space on hard disks in which configuration information for each dynamic disk is located on the disk space beyond the first physical sector. This configuration information is stored outside of any volume on the hard disk. (10)
See error-correcting code.
See enhanced capabilities port (ECP) mode.
A subpackaging of a Windows revision that contains the core OS plus a special set of features that is offered as a separate product targeted to a certain type of end user. (8)
Electrically erasable programmable ROM. A ROM chip that is erasable using an electrical charge. (2)
See Encrypting File System (EFS).
See Enhanced IDE.
electromagnetic interference (EMI)
The disruption of signal transmission caused by the radiation of electrical and magnetic fields. Electric motors are a common source of EMI. (18)
electromagnetic pulse (EMP)
A large burst of electromagnetic energy, as from a nuclear explosion, that has the potential to damage communications and power lines within a large geographic area, depending on the size and location of the pulse. (16)
electronic KVM switch
A KVM switch that uses software and special keyboard commands to switch among controlled computers. Also called anactive KVM switch. (3)
In a laser printer, a metal drum with an electro-photosensitive coating to which a charge can be applied by a laser beam. (12)
electrostatic discharge (ESD)
The sudden and uncontrolled movement of electricity from an object with a greater charge to one with a lesser charge. Also called static electricity. (18)
A special-purpose computer designed for a certain task and installed within a device. (2)
emergency repair disk (ERD)
A special disk used for recovering an OS failure in Windows 2000. It requires that you create the ERD while the system is healthy, and then use it, along with the Windows Setup CD, to repair Windows. (11)
Emergency Repair Process
A Windows 2000 recovery tool requiring an up-to-date emergency repair disk (ERD) or recent emergency repair information stored on the local hard disk. (11)
See electromagnetic pulse.
Enable Boot Logging
An Advanced Options menu choice that creates a log of the Windows startup in a file named NTBTLOG.TXT and saved in thesystemroot folder (normally C:\Windows). (11)
Enable Low Resolution Video
In Windows Vista and Windows 7, an Advanced Options menu choice that starts Windows normally, except that the video mode is changed to the lowest resolution, using the currently installed video driver. This option does not switch to the basic Windows video driver. (11)
Enable VGA Mode
In Windows 2000 and Windows XP, an Advanced Options menu choice that starts Windows normally, except that video mode is changed to the lowest resolution, using the currently installed video driver. This option does not switch to the basic Windows video driver. (11)
A security service in which authentication credentials are encrypted (user name and password) before transmission over a network. (16)
Encrypting File System (EFS)
A security feature of many Windows versions that allows it to encrypt files on an NTFS volume. (16)
The conversion of data into a special format that cannot be read by anyone unless they have a software key to convert it back into its usable form. (13)
enhanced capability port (ECP) mode
A mode for parallel ports that allows access to special features in the PC called DMA channels. This mode is approximately ten times faster than regular bidirectional mode and is designed for printers and scanners. (4)
Enhanced IDE (EIDE)
A standard for hard drives that attach to the Parallel AT Attachment (PATA) interface. (1)
enhanced parallel port (EPP) mode
A parallel port mode that has the same performance as ECP but is used with parallel devices other than printers and scanners. (4)
See enhanced parallel port (EPP) mode.
Erasable programmable read-only memory. A ROM chip that is erasable and reprogrammable through the use of specialized software. (2)
In a laser printer, a high-intensity lamp that, when shone on a portion of the electro-photosensitive drum, removes any remaining charge on that portion of the drum. (12)
See emergency repair disk.
error-correcting code (ECC)
A method of memory error-checking that is more sophisticated than parity checking. Like parity checking, it adds an extra bit per byte. In addition, software in the system memory controller uses an algorithm to both detect and correct errors. (2)
See External Serial ATA.
A group of networking standards created by the IEEE 802.3 subcommittee. (13)
A memory error-checking method in which the parity bit is used to ensure that the total number of 1s in the data stream is even. (2)
See Extended Video Graphics Array.
In router configuration, a term that is used to describe traffic that is allowed, as in allowing traffic using a certain port number through the router. (16)
A grouping of wires built into a PC that, based on certain protocols, transfers data, control signals, and power to printed circuit boards (adapter cards) that are plugged into connectors in the expansion bus. Technicians often use the termsexpansion bus, bus, and system bus interchangeably. (1)
See adapter card.
A PCMCIA card standard that comes in two interfaces: PCIe and USB 2.0. (6)
A partition type that can exist on a basic disk and have one or more logical drive letters assigned to it. A Windows operating system cannot boot from an extended partition. (10)
Extended Video Graphics Array (EVGA)
A VESA standard for graphics adapters with a maximum graphics resolution of 1024 × 768 pixels. (3)
See parts grabber.
A long-handled tool with a magnet on one end, used to pick up small objects containing iron. (5)
In a CPU, special memory that resides outside the CPU's core and is used to temporarily store instructions and data in order to increase the processing speed. Also called Level 2 (L2) cache and Level 3 (L3) cache, depending on the design of the CPU and motherboard. (1)
External Serial ATA (eSATA)
An extension of the SATA standard for external SATA devices, with speeds triple that of USB 2.0. (1)
Using the same cabling as 10BaseT, Fast Ethernet, or 100Base-T, operates at 100 Mbps and uses different network interface cards. (13)
fast page mode (FPM)
An early technology for increasing the performance of DRAM. (2)
See FAT file system.
FAT file system
A file system in which one of the basic structures is a table used for allocating space. This table is called the file allocation table (FAT). (10)
See file allocation table.
A version of the FAT file system for very small drives—mainly for floppy drives, using a 12-bit file allocation table. (10)
A version of the FAT file system used by MS-DOS for hard drives, using a 16-bit file allocation table. (10)
A version of the FAT file system used by hard drives and some flash drives (thumb drives, etc.), using a 32-bit file allocation table. (10)
See floppy disk drive.
A cable medium that transmits light pulses rather than electrical signals, so it is not susceptible to electromagnetic interference (EMI). (13)
field replaceable unit (FRU)
A component that you can install into a system onsite, such as memory modules, heat sinks, and CMOS batteries. (5)
Information organized as a unit into a container. The author (creator) of a file controls how much information the file contains. (10)
file allocation table (FAT)
The file system component in the FAT file system in which the OS creates a table that serves as a map of where files reside on disk. Also called the FAT table. (10)
file signature verification
A process applied to digitally signed code to unencrypt the signature data and use the information to verify the program code was not modified since the signature was added. (9)
The logical structure on disk that allows the operating system to save and retrieve files. Examples of file systems are FAT and NTFS. Both of these file system have different versions, such as FAT12, FAT16, FAT32, and NTFS 4.0 and NTFS 5.0. (10)
File Transfer Protocol (FTP)
A protocol for computer-to-computer (host-to-host) transfer of files over a TCP/IP network, regardless of the operating system in use. (13)
A computer (or dedicated device) that sits between a private network and an untrusted network and examines all traffic in and out of the network it is protecting. It will block any traffic it recognizes as a potential threat, using a variety of techniques. (16)
See IEEE 1394.
Software instructions stored in ROM chips. It exists on most PC components and on the motherboard. (1)
fixed input power supply
A power supply that only accepts one input power voltage. (6)
BIOS that can be electronically upgraded. (1)
See thumb drive.
A type of solid-state storage that is commonly used in a variety of devices, such as digital cameras, which often use CompactFlash. (2)
A technology for ROM that can be reprogrammed using special software. (2)
The act of electronically upgrading BIOS. (5)
flat panel display (FPD)
A computer display that uses liquid crystal or plasma technology and does not require the bulk of a large picture tube. The screen enclosure can be as thin as one to two inches. (3)
floating-point unit (FPU)
A type of arithmetic logic unit (ALU) that is used to perform specialized functions, such as division and large decimal number operations. Also called a math coprocessor. (1)
A magnetic storage device that contains a thin internal plastic disk, capable of receiving magnetic charges contained in the thin magnetic coating on the disk. (1)
floppy disk drive
A drive used for reading from and writing to removable floppy disks. Also called FDD. (1)
A special modifier key on a laptop keyboard that when pressed together with certain alphanumeric keys, changes the output of the pressed key. It is often called the function key. (6)
In Disk Management, the status given to a dynamic disk that has not had its configuration information (stored on the disk) imported into Windows. This status occurs when a dynamic disk is moved to a different Windows computer or when a dynamic disk fails. (10)
On a motherboard, the type and location of components, as well as the size of the board itself. (1)
A process that places the logical structure of a file system on a partitioned volume. (4)
See fast page mode.
See floating-point unit.
A type of switched network used by phone companies. (13)
The use of deceit and trickery to persuade someone to hand over money or valuables. (16)
front side bus (FSB)
An internal bus in a CPU that connects it to memory and video. (1)
See front side bus.
See File Transfer Protocol (FTP).
In reference to networks, communications in both directions at the same time. (13)
In the laser printing process, the step at which the heat-sensitive toner is fused to the paper by heated fusing rollers. (12)
In a laser printer, the lamp that heats the fusing rollers. (12)
In the laser printer, the heated rollers that fuse the toner to the paper. (12)
A small program, such as those that can be run from the Windows Sidebar. (8)
Also called 1000Base-T, this networking standard supports speeds up to 1 Gbps. (13)
Global System for Mobile communications (GSM)
The cellular network standards used by AT&T and T-Mobile. (13)
graphical processing unit (GPU)
A processor on a graphics adapter used to render graphics images for the display, saving the CPU for other functions. (1)
graphical user interface (GUI)
A user interface that takes advantage of the video system's graphics capabilities for manipulated graphic elements that represent objects and tasks. (8)
See digitizing tablet.
Threats that are not truly malicious code, but can have indirect negative effects, such as decreasing performance or using up bandwidth. Grayware includes spyware, adware, spam, and spim. (16)
See antistatic mat.
A perpetrator of malicious software attacks against computers and networks. Also called a cracker. (16)
In networks, when data can travel in either direction, but only in one direction at a time. (13)
hard disk drive
A magnetic storage device that stores data on metal platters that have a coating that holds data in the form of changes to small magnetic particles in the coating. Also called HDD. (1)
hardware abstraction layer (HAL)
A component of the Windows operating system that resides in a file and is loaded into memory during the kernel loading phase of the Windows startup. (10)
See hard disk drive.
The high-definition optical disc formatting standard, promoted by Toshiba, that was defeated by the Blu-ray Disc standard as the widely accepted high-definition standard. (2)
See High-Definition Multimedia Interface.
A heat dissipation device, usually a passive metal object with a flat surface attached to a component, such as a chip. (3)
heat sink compound
See thermal compound.
A CRT video setting, also known at horizontal hold, that holds the image horizontally on the screen. (3)
A Windows sleep mode that uses hard drive space to save all the programs and data that are in memory at the time you choose this mode. The computer then completely shuts down and requires no power while it is hibernating. (6)
A file attribute that is given to a file to indicate it should not be visible in Windows Explorer unless View settings override the attribute and allow the file to be shown.
High-Bandwidth Digital Content Protection (HDCP)
A feature of HDMI that prevents people from illegally copying HD DVDs. See also High-Definition Multimedia Interface (HDMI). (3)
High-Definition Multimedia Interface (HDMI)
An interface standard for use with DVD players, digital television (DTV) players, set-top cable or satellite service boxes, and other devices. It combines audio and video signals into an uncompressed signal and has a bandwidth of up to 5 GB/second. Only one specially designed cable is required where previously several were required. (3)
high-voltage power supply (HVPS)
Any power supply that provides high voltage, such as those in laser printers and CRTs. (3)
A setting on an LCD display that adjusts the viewable area of the display horizontally. (3)
A physical area where a Wi-Fi network connects to the Internet. (13)
The act of safely installing/uninstalling or attaching/removing a device while a computer is up and running. (3)
A drive that can be safely installed and removed while a computer is up and running without damaging the data stored on the drive. (2)
See Hypertext Markup Language (HTML).
See Hypertext Transfer Protocol (HTTP).
 A device that is the central connecting point of a LAN. A hub is little more than a multiport repeater taking incoming signals on one port and repeating them to all other ports. Ethernet hubs have been largely replaced by Ethernet switches. (13).  A multiport connecting device for USB devices. (4)
A CPU technology that allows two threads to execute at the same time within a single execution core. This technology is considered to be partially parallel execution. Intel introduced it in the Pentium 4 Xeon CPU. Also known as simultaneous multithreading (SMT). (1)
Hypertext Markup Language (HTML)
The language of Web pages. Web designers use the HTML language to create Web page code, which your Web browser converts into the pages you view on your screen. (13)
Hypertext Transfer Protocol (HTTP)
The information transfer protocol of the World Wide Web (WWW). Included in HTTP are the commands Web browsers use to request Web pages from Web servers and then display them on the screen of the local computer. (13)
Hypertext Transfer Protocol over Secure Sockets Layer (HTTPS)
A protocol for securing data for transmission by encrypting it. (13)
An assigned address or range of addresses on a system's address bus that, together with an interrupt request line (IRQ), allows a device to be recognized by the processor. (5)
See Internet Control Message Protocol.
In an operating system GUI, a tiny graphic representing an application, folder, disk, menu item, or other entity. (8)
See Integrated Drive Electronics.
This occurs when someone collects personal information belonging to another person and uses that information to fraudulently make purchases, open new credit accounts, and even obtain new driver's licenses and other forms of identification in the victim's name. (16)
A slide switch on the exterior of a PC power supply used to switch between two input voltages.
The Institute of Electrical and Electronics Engineers, an international nonprofit organization that sets standards as part of its charter. (3)
A parallel interface standard that supports bidirectional communication and transfer rates of up to 2 MBps. (3)
An external serial bus standardized by the IEEE. Apple first developed it as FireWire. Other manufacturers call it i.link or Lynx. It can support up to 63 daisy-chained devices. Since the introduction of the faster update, IEEE 1394b, the original standard is called IEEE 1394a. (3)
The original version of the IEEE 1394 standard that supports speeds up to 400 Mbps. (3)
The second version of the IEEE 1394 standard; it supports speeds up to 3.2 Gbps and distances of up to 100 meters. (3)
The third version of the IEEE 1394 standard; it is a departure from the old standards in that it uses Category 5e twisted pair cable with RJ-45 connectors, combining Ethernet and FireWire. (3)
See Internet Message Access Protocol (IMAP).
A type of printer that transfers ink to paper by causing a print head to strike a printer ribbon containing ink against the paper. (12)
inactive KVM switch
A type of KVM switch that is controlled through a mechanical switch on the box. (3)
Independent Basic Service Set (IBSS)
A small group of computers communicating wirelessly with one another without the use of a centralized wireless access point (WAP). (14)
industry standard architecture (ISA)
A very old expansion bus standard, seen in the early IBM PC. (1)
Light waves in the infrared spectrum. (6)
Infrared Data Association (IrDA)
An organization that creates specifications for infrared wireless communication. (6)
A wireless mode requiring a wireless access point (WAP). (14)
A small cassette containing an ink reservoir used to provide the medium for certain printers. An ink cartridge will only fit a certain model printer. (12)
A type of printer that uses one of several technologies to apply wet ink to paper to create text or graphic printouts. The two most popular inkjet printer models are the InkJet, developed by Hewlett-Packard, and the Bubble Jet, developed by Canon. Epson uses the term "ink jet" (with a space), but it does not appear in the model names of their printers. (12)
In reference to computers, the pathways or methods for what goes into a computer in the form of data and instructions and similarly what comes out of the computer in many forms, including an onscreen display, a printout sent to a printer, or data sent to another device or computer. (1)
Integrated Access Device (IAD)
A device that converts digital signals from the broadband connection to voice for the analog phone and the analog voice signals to digital signals for the digital network. (14)
Integrated Drive Electronics (IDE)
An early PC hard drive interface. (1)
Integrated Service Digital Network (ISDN)
An early international standard for sending voice and data over digital telephone wires. ISDN uses existing telephone circuits or higher-speed conditioned lines to get speeds of either 64 Kbps or 128 Kbps. ISDN lines also have the ability to carry voice and data simultaneously over the circuit. (13)
One of the two prevailing CPU manufacturers. (1)
Intel x86 Specification
An Intel specification for the PC 32-bit architecture defining CPUs, motherboards, and other components. (5)
The bus within a CPU that connects the CPU to external components. (1)
internal cache memory
In a CPU, special memory that resides within the CPU's core and is used to temporarily store instructions and data in order to increase the processing speed. Also called L1 cache. (1)
InterNational Committee on Information Technology Standards (INCITS)
A standards organization, of which the T10 SCSI committee maintains the SCSI standard. (4)
The worldwide interconnection of networks that can be accessed with various Internet-based software. The World Wide Web is one of the many services of the Internet. (13)
Internet Control Message Protocol (ICMP)
A subprotocol of IP that detects and reports problems that can cause errors. (15)
Internet Explorer (IE)
A Web browser created by Microsoft. (14)
Internet Message Access Protocol (IMAP)
A protocol used by e-mail clients for communicating with e-mail servers. This protocol is replacing the POP protocol. IMAP allows users to connect to e-mail servers and not only retrieve e-mail, which removes the messages from the server, as they can do with the POP protocol, but also manage their stored messages without removing them from the server. (13)
Internet Protocol (IP)
One of the main protocols of the TCP/IP protocol suite, IP manages logical addressing of network packets so routing protocols can route the packets over the network. (13)
Internet service provider (ISP)
A company in the business of providing Internet access to users. (13)
An interconnected network. The Internet is the largest example. (13)
interrupt request line (IRQ)
An assigned channel over which a device can send a signal to the processor to get its attention. (5)
A private internetwork. (13)
A device that converts DC current to AC. An inverter is required in a laptop to provide the AC current required by the display. (6)
IP packet filtering
A firewall service that inspects (or filters) each packet that enters or leaves the network, applying a set of security rules defined by a network administrator, and not allowing packets that fail inspection to pass between networks. (16)
A network connection device that routes IP packets between networks. (13)
A command-line utility installed on a Windows computer with the TCP/IP protocol suite; it's used to view the IP configuration of a network connection and to perform certain administrative tasks. (15)
See interrupt request line.
See Integrated Service Digital Network.
See Internet service provider.
The use of words, often technical and uncommon, that both parties understand in the same way. (18)
See thumb drive.
On a circuit board, a small connector that slides down on a pair of pins jutting up from the board. Multiple pins are often side-by-side, and a jumper joins a pair of them. (4)
A small device containing a microchip used to generate unique passwords for logging on to a computer or a network. (16)
A hardware device or a program that monitors and records a user's every keystroke, usually without the user's knowledge. (16)
KVM over IP
A remote KVM switch that captures the keyboard, video, and mouse signals, encodes them into IP packets, and sends them over an IP network. (3)
A device that in its traditional configuration as a local KVM switch connects a single keyboard, video display, and mouse to two or more computer systems, allowing the user to switch control from one computer to another. (3)
See internal cache memory.
See local area network.
A raised area on an optical disc that is alternated with depressed areas to be interpreted as data. (2)
land-grid array (LGA)
A processor packaging that uses pads on the processor that come in contact with pins in the socket on the motherboard, permitting a higher density than possible with PGA. (4)
A laptop is a small, easily transported computer, generally weighing less than 7 pounds and with roughly the same dimensions as a 1- to 2-inch-thick stack of magazines. Laptops computers have an all-in-one layout in which the keyboard, and often the pointing device, is integrated into the computer chassis and an LCD display is in a hinged lid. (6)
A coherent and concentrated light beam, also simply called a laser. (12)
A printer that uses a light beam (laser) in the printing process. (12)
Last Known Good Configuration
A Windows Advanced Options menu choice that restores a group of registry keys containing system settings such as services and drivers. These are the last settings that worked, and you have only a narrow window of opportunity to use Last Known Good—on the first reboot after making a configuration change and before logging on. Also called Last Known Good (LKG). (11)
The amount of time it takes a packet to travel from one point to another. (13)
See logical block address.
See liquid crystal display.
Light emitting diode, a tiny bulb light found on many devices, often used to indicate operational status. (5)
The black box that appears around an image, such as a widescreen video when it is displayed on a screen with a 4:3 aspect ratio. (3)
Level 1 (L1) cache
See internal cache memory.
Level 2 (L2) cache
See external cache.
Level 3 (L3) cache
See external cache.
See lithium-ion (Li-ion) battery.
A printer that creates printed output line by line. (12)
liquid cooling system
A cooling system that uses liquid to transfer heat away from components. (3)
liquid crystal display (LCD)
A display device that uses liquid crystals to display images. (3)
A pixel that is permanently turned on, causing the pixel to show constantly as red, green, or blue. Also called a stuck pixel. (7)
lithium-ion (Li-ion) battery
A type of rechargeable battery used in laptops and other portable devices. (6)
local area network (LAN)
A network that covers a relatively small area, such as a building, home, office, or campus. The typical distances are measured in hundreds of meters. (13)
local group account
In Windows, a security account that contains one or more local user accounts, and when a computer is a member of a Windows domain, may also contain domain user or group accounts. (16)
local KVM switch
See KVM switch.
local remote KVM switch
A remote KVM switch that uses either Cat 5 or USB cabling. The distance it can be from the computers it controls is a function of the length limits of the cabling; it normally uses a proprietary protocol and special hardware.
local user account
A security account that exists in a local security accounts database. (16)
logical block address (LBA)
A method for supporting up to 8.3 GB capacity hard drives. Both the BIOS and hard drive system must use LBA. (1)
long filename (LFN)
A file or folder name that breaks the 8.3 file-naming convention used in the FAT file system. This term continues to be used on newer file systems. (10)
A plug designed for testing a specific port type (e.g., serial, parallel, or USB). The plug does not connect to a cable but reroutes the sending pins to the receiving pins. Using special software on the computer, a loopback test is performed in which signals are both sent and received. (5)
low-voltage differential (LVD)
A technology for transferring serial data at high speeds. Also known as low-voltage differential signaling (LVDS). (3)
low-voltage differential signaling (LVDS)
See low-voltage differential.
A name used by the Windows operating systems to identify any parallel port. (5)
The name used by the Windows operating systems to identify the first parallel port. (5)
The name used by the Windows operating systems to identify the second parallel port. (5)
Lucent connector (LC)
A fiber-optic connector that has a snap coupling and, at 1.25 mm, is half the size of the SC connector. Also called a local connector. (13)
The signal in a television transmission that contains the brightness of the image. (3)
See low-voltage differential (LVD).
See low-voltage differential signaling (LVDS).
See Media Access Control (MAC) address.
magnetic mass storage
Device that stores digital data on magnetized media, such as floppy disks, the metal platters in hard disk drives, and magnetic tape media used in tape drives. (1)
Software created to perform malicious acts. Also called malicious software. (16)
mass storage device
A device that stores a large amount of information, even when it is powered off. (1)
master boot record (MBR)
The first physical sector on a hard disk, which contains the initial boot program that the BIOS loads into memory during bootup. It also contains the partition table. (10)
The role of the first EIDE drive on a PATA channel. (4)
master file table (MFT)
A part of the NTFS file system used to store a transaction-based database, with all file accesses treated as transactions, and if a transaction is not complete, NTFS will roll back to the last successful transaction.
material safety data sheet (MSDS)
A standardized document that contains general information, ingredients, and fire and explosion warnings as well as health, disposal, and safe transportation information about a particular product. Any manufacturer that sells a potentially hazardous product must issue an MSDS for it. (18)
See floating-point unit.
See master boot record.
Mechanical Transfer Registered Jack (MT-RJ) connector
A fiber-optic connector that resembles an RJ-45 network connector and is less expensive and easier to work with than ST or SC connectors. (13)
Media Access Control (MAC) address
The hardware address of a network device, also called the Ethernet address (on Ethernet devices) or NIC address. (13)
A compartment in a portable computer's case that holds a single media device that can be swapped with another. For instance, you may swap an optical drive, a secondary hard drive, or a floppy drive into and out of a single bay. (6)
A computer's temporary working space, usually in DRAM chips. (2)
A logical memory address defined in a processor's address bus that allows the system to access physical RAM or ROM memory locations. (3)
In reference to a memory module, the number of memory modules required to match the data bus width of the processor. (2)
memory controller chip (MCC)
The portion of the chipset that controls communications between the CPU and system RAM. (1)
metropolitan area network (MAN)
A network that covers a metropolitan area, usually using high-speed fiber-optic cable (operating in the gigabits-per-second range). (13)
One of many low-level instructions built into the control unit of a CPU. Also called a microprogram. (1)
A RAM module designed for subcompact and laptop computers. It is half the size of a SoDIMM module. (6)
Microsoft Management Console (MMC)
Introduced in Windows 2000, a user interface for Windows administration tools that is flexible and configurable. (8)
Microsoft Product Activation (MPA)
Microsoft's product activation program. (9)
Microsoft Windows Vista Home Premium
A version of Windows Vista that includes Windows Media Center, which supports advanced multimedia functions. (2)
Microsoft Windows XP Media Center
A version of Windows XP that includes Windows Media Center, which supports advanced multimedia functions. (2)
See musical instrument digital interface.
MIMO (multiple input/multiple output)
A technology that makes 802.11n speeds possible, using multiple antennas to send and receive digital data in simultaneous radio streams that increases performance. (13)
A standard used in laptops that is based on PCI. The biggest difference is that Mini PCI is much smaller than PCI—both the card and the slot. Mini PCI has a 32-bit data bus. (6)
Audio connectors that use a 1/8" single pin plug. (3)
A common connector used to connect a power supply to floppy drives. (3)
A connector commonly used for PC keyboards. It is much smaller than the original DIN connector. (3)
The smallest laptop type, weighing less than 3 pounds. See also netbook and mini-notebook. (6)
Two disk drives used for RAID 1, in which data is written to both drives at the same time, a practice called mirroring. (2)
The act of writing to two disk drives at the same time, creating identical drives. (2)
See Microsoft Management Console.
Slang for motherboard. (1)
The practice, mostly among gamers, of modifying a computer case. (1)
In fiber-optics, a single light wave passing down a cable. (13)
Traditionally, this term only applied to the type of device described in the definition for analog modem. Now, it is also used for the digital devices in DSL and cable data communications. (2)
A common connector used to connect a power supply to internal peripherals. (3)
The circuit board in a computer to which all other components directly or indirectly connect. Also called a mainboard, system board, mobo, or planar board. (1)
The connecting point of a mounted drive to a folder on an NTFS volume. (10)
A drive that is mapped to an empty folder on an NTFS volume and is assigned a drive path rather than drive letters. (10)
The filename for the System Configuration Utility, which allows you to test various scenarios for Windows startup for troubleshooting purposes. (11)
See System Information.
multifunction device (MFD)
A device that combines two or more devices, such as a printer, scanner, and fax machine. (12)
multifunction printers (MFDs)
A printer that includes one or more other functions, such as a scanner and fax machine. (12)
The use of two or more video adapters (hence the term "GPU") to drive a single display for the purpose of increasing performance. (3)
Multilingual User Interface (MUI)
The code used to provide multiple language support to Windows. (9)
Multimedia Terminal Adapter (MTA)
On a cable network, the device used at the customer site for the analog/digital conversion. (14)
A handheld device used to measure electrical resistance, voltage, and/or current. (5)
multimode fiber (MMF)
Fiber-optic cable in which multiple light waves can pass simultaneously. Usually larger in diameter than single-mode fiber; and each wave uses a certain portion of the fiber cable for transmission. (13)
The use of more than one monitor on a single computer. (3)
In telecommunications, a technique that combines multiple messages or signals onto a single transmission channel. (13)
musical instrument digital interface (MIDI)
A standard for interconnecting electronic musical instruments to communicate with computers and among themselves. (3)
See network address translation.
A non-routable network protocol suite for use only in small networks. (13)
A protocol developed in the 1980s by IBM for managing names on a network. Also used by Microsoft in early networking. Replaced by DNS on TCP/IP networks. (13)
A scaled-down laptop in the ultra-portable category, designed for Internet access. See also ultra-portable and mini-notebook. (6)
A command-line command, installed with the TCP/IP protocol suite, which provides statistical information about the TCP/IP protocols and network connections involving your computer, depending on the switches you use when you enter the command. (15)
network address translation (NAT)
A TCP/IP protocol developed as a solution to the dwindling number of IP addresses on the Internet and that also serves to hide IP addresses on a private network from the Internet. (16)
Software that runs on the computers in a network and that receives services from servers. (13)
network interface card (NIC)
An adapter used to connect a computer or other device to a network medium. (13)
network operating system (NOS)
An operating system that runs on a network server and provides file sharing and access to other resources, account management, authentication, and authorization services. (13)
New Low-profile eXtended (NLX)
An Intel standard for motherboards targeted to the low-end consumer market that includes built-in components, while saving space and fitting into a smaller case. (1)
See network interface card.
nickel metal hydride (NiMH) batteries
A now-obsolete type of rechargeable battery used in laptops and other portable devices, replaced by lithium-ion batteries. (6)
The type of battery used in the first portable PCs, which was heavy and inefficient. (6)
See nickel metal hydride.
See New Low-profile eXtended.
Memory that does not require power to keep stored data intact. Also called flash memory. (2)
One or more chips in a computer's chipset that controls communications between the CPU and RAM on the motherboard. (1)
A command-line utility, installed with the TCP/IP protocol suite, that is used to troubleshoot DNS problems by querying DNS name servers and displaying the results of the queries. (15)
The default Windows file system that includes many important features, including encryption and permissions. (10)
In Microsoft Windows, NTFS permissions are used to specify and control which users and groups can access certain files and folders and what each user or group can do with them. (10)
The boot loader file in Windows 2000 and Windows XP. During the boot loader phase, NTLDR takes control of the system, switches the CPU to protected mode, starts the file system, and reads the BOOT.INI file. (10)
See optical character recognition.
A memory error-checking method in which the parity bit is used to ensure that the total number of 1s in the data stream is odd. (2)
optical character recognition (OCR)
Software that takes a scanned image and interprets the patterns in the image into alphanumeric characters. (12)
A disc drive that uses laser technology to read and/or write to special discs. (2)
original equipment manufacturer (OEM)
In regard to Windows operating systems, a version of Windows that is designed to work with a certain manufacturer's equipment. (9)
The practice of forcing a CPU or other computer component to run at a higher clock rate than the manufacturer intended. (1)
P1 power connector
A 20- or 24- pin connector that supplies power from a PC's power supply to the motherboard. (3)
A 4-pin connector that, in addition to a 20-pin connector, is part of motherboard power connector that follows the ATX 12V standard. (3)
See paging file.
A file used by Windows for virtual memory. Also called the swap file. The actual filename in Windows is PAGEFILE.SYS. (9)
Parallel AT Attachment (PATA)
A hard drive interface that transfers data in parallel. EIDE and ATAPI drives attach to the PATA interface. (1)
An interface on a PC that originally was unidirectional and operated at a speed of 150 KBps, but now has several operation modes. (2)
A type of memory checking in which every eight-bit byte of data is accompanied by a ninth bit (the parity bit), which is used to determine the presence of errors in the data. The two types of parity are odd and even. (2)
(n.) An area of a physical hard disk that defines space that will be used for logical drives. (4). (v.) To define the space to be used for logical drives using a special program, such as the Windows Setup program. (9)
The style of partition on a basic disk, which includes primary and extended. (10)
A pen-sized tool that has a plunger at one end. When pressed, the plunger causes small, hooked prongs to extend from the other end of the tool for retrieving dropped objects from inside a computer. (5)
passive matrix display
An LCD display using an old technology that has a grid of horizontal and vertical wires with a transistor at the end of each wire. When two transistors (one at the x-axis and one at the y-axis) send voltage along their wires, the pixel at the intersection of the two wires lights up. (3)
A string of characters that a user enters, along with an identifier, such as a user name, in order to be authenticated. (16)
A program used to discover a password. (16)
A software fix for a single problem. (8)
The early standard developed by PCMCIA for credit-card-sized devices used in laptops. (6)
See peripheral component interconnect.
PCIe (peripheral component interconnect express)
An expansion bus architecture that uses serial communications rather than the parallel communications of PCI. Also called PCI Express and PCI-E. (1)
PCIe Mini Card
The successor to the Mini PCI. It has a 64-bit data bus and is half the size of a Mini PCI Card. (6)
A network in which all of the computers essentially operate as both servers (providing access to shared resources) and clients (accessing those shared resources). (13)
A utility in Windows NT for gathering and viewing performance data involving memory, disks, processors, network, and other objectives. (11)
peripheral component interconnect (PCI)
Introduced in 1993, the most common expansion bus architecture in PCs in the mid 1990s. It transfers data in parallel over a data bus that is either 32- or 64-bits wide. (1)
permanent virtual circuit (PVC)
A virtual communication circuit that is created and remains available between two endpoints, which are normally some form of data terminal equipment (DTE). Telecommunications companies provide PVC service to companies requiring a dedicated circuit between two sites that require communications that are always on. (13)
In networking, the authorization to access a computer or resource on a computer. Specific permission levels include read, change, modify, etc. (16)
personal area network (PAN)
A communications network made up of personal computing devices, such as computers, telephones, and personal digital assistants. (13)
Personal Computer Memory Card International Association (PCMCIA)
An organization that creates standards for laptop computer peripheral devices. (6)
Personal Digital Assistant (PDA)
A portable computer small enough to fit in your hand, also referred to as a "palmtop" computer. Because it is so small, a PDA does not have the functionality of a laptop or desktop computer. In other words, a typical PDA allows you to perform only a small number of functions. (6)
See software firewall.
See pin grid array.
A variation of the PGA CPU packaging that was used with Pentium CPUs. (4)
A fraudulent method of obtaining personal and financial information through the use of pop-ups or e-mail messages that purport to be from a legitimate organization, such as a bank, credit card company, or retailer. (16)
pin grid array (PGA)
A term used for CPU packaging that indicates that a chip has columns and rows of pins. (1)
A command-line tool installed with the TCP/IP protocol suite that is used for testing communications between two hosts. (15)
pinned items list
An area on the top left of the Windows XP Start menu containing shortcuts to Windows Update and programs for browsing the Internet and using e-mail. (8)
A diagram showing the purpose of each wire in a connector. (4)
A depressed area on an optical disc that is alternated with raised areas to be interpreted as data. (2)
A single dot on a display screen. A contraction of "Picture Element." (3)
plain-old telephone service (POTS)
The traditional wired telephone network. (13)
plug and play (PnP)
A system by which the computer BIOS and operating system recognizes a device and the operating system automatically installs and configures a device driver. (3)
See pointing stick.
A pointing device built into some laptop keyboards. It appears to be a very tiny joystick-type button that barely protrudes above the level of the keys. (6)
point-to-point protocol (PPP)
A protocol that allows two devices to connect, authenticate, and negotiate what protocols they will use (almost always TCP/IP). (16)
Point-to-Point Tunneling Protocol (PPTP)
An enhanced version of PPP, which adds the ability to secure the point-to-point connection with encryption. (16)
See Post Office Protocol.
A program that blocks browser pop-ups. (17)
A virus that downloads to a user's computer through a pop-up window that appears in a Web browser. It requires an action on the part of a user, such as clicking a button that implies acceptance of something like free information. (16)
A connection point on a device or computer, sometimes called a socket. (3)
A device used with a laptop. The port replicator remains on the desktop with external devices connected to ports on it. A laptop then needs only one connection to the port replicator to have access to the peripherals. (6)
The redirection of incoming traffic to the requesting internal hosts that initiated the communication with an external host. (16)
Any type of computer that you can easily transport and that contains an all-in-one component layout. (6)
See power-on self-test.
An adapter card used to run a special diagnostic test on a computer as it is powering up. These tests usually go beyond those performed by the system BIOS-based POST. (5)
Post Office Protocol (POP)
The protocol used to allow client computers to pick up e-mail from mail servers. The current version is POP3. (13)
See plain-old telephone service.
A group of features in the system BIOS, the chipset, the operating system, device drivers, and the individual components that enable efficient use of power in a computer. (6)
A power-usage level. (6)
The component that provides power for all components on the motherboard and internal to the PC case. Also called a power supply unit (PSU). (3)
power supply tester
A specialized device for testing a power supply unit that comes with connectors compatible with the output connectors on a standard power supply. (5)
power supply unit (PSU)
See power supply.
power-on self-test (POST)
A group of tests, stored in the BIOS and performed as a PC boots up, to check for the presence and function of system components. (1)
See point-to-point protocol.
See Point-to-Point Tunneling Protocol.
A joke program that produces strange behavior, such as screen distortions, erratic cursor behavior, or strange icons to appear on the screen. (16)
Preboot eXecution Environment
An Intel standard for starting up a computer over the network, without relying on a disk-based operating system. Used to install a new operating system or run diagnostics software. (13)
primary corona wire
In a laser printer, a wire that stretches across the printer's drum, not touching it, but positioned very close to the drum's surface so it can pass high voltage to the drum. (12)
In reference to IDE PATA drives, the master drive on the first channel. (4)
A partition type on a basic disk that can have only one logical drive assigned to it encompassing the entire partition. This partition type is also the only type of partition on a basic disk that can be marked as active for booting up an operating system. (10)
In reference to IDE PATA drives, the slave drive on the first channel. (4)
The memory space, program code, data, and system resources required by a running program. (11)
An identifier assigned to a process when it starts. (11)
process priority level
A value assigned to a process that controls the order in which the program code is executed in relation to other code. (11)
See central processing unit.
Another name for a motherboard in a laptop. (6)
A set of wires used by data traveling into and out of a processor. (1)
A set of behaviors for the workplace that includes how you interact with people and how you treat property. (18)
Program Compatibility Wizard
A Windows wizard that sets options for starting and running a specific old program that will not otherwise run properly in Windows. (8)
A device that takes video output and projects it onto a screen for viewing by a larger audience. (3)
Programmable ROM. A ROM chip that can have programs added to it. (2)
In networking, this is a set of rules for using network hardware and software. In most discussions about networks, this term is assigned to certain network software components. (13)
A network service that handles the requests for Internet services, such as Web pages, files on an FTP server, and mail for a proxy client without exposing that client's IP address to the Internet. There is specific proxy server and client software for each type of service. (13)
Personal System/2, as in PS/2-style mice and keyboards and connectors. Also called mini-DIN connectors. (3)
public switched telephone network (PSTN)
The worldwide network that carries traditional voice traffic. (13)
See permanent virtual circuit.
A CPU containing four CPU cores. (1)
Quick Launch bar
An optional toolbar you can add to the taskbar just to the right of the Start button. Shortcuts on this bar launch with a single-click. (8)
radio frequency (RF)
Signals broadcast through the air. (4)
A RAID array in which every time data is written to disk, a portion (block) is written to each disk in turn, creating a "stripe" of data across the member disks. RAID 0 uses the total disk space in the array for storage, without protecting the data from drive failure. (2)
Also called mirroring, this RAID array type provides fault tolerance because all the data is written identically to the two drives in the mirrored set. (2)
Also called striping with distributed parity or striping with interleave parity, this RAID method involves a set of disks in which every time data is written to disk, a portion is written to each disk in turn, creating a "stripe" of data across the member disks. However, in each stripe, the portion on one disk is not the actual data, but the result of an algorithm performed on the data contained in the other blocks in the stripe. This block is called the parity block, and because of the space required, the total disk space in the array available for data storage is equal to the total disk space less one entire disk. (2)
Two or more disks working together in one of the several RAID schemes. (2)
Specialized hardware used to create and manage a RAID array. (2)
See random access memory.
Rambus Dynamic RAM (RDRAM)
Memory chips that use a special Rambus channel that has a data transfer rate of 800 MHz. A double channel width results in a 1.6 GHz data transfer. RDRAM sticks use special RIMM slots. (2)
RAMBUS Inline Memory Module (RIMM)
Both the connectors on the RDRAM memory modules and the motherboard sockets (or slots) that match them. (1)
random access memory (RAM)
Memory that is accessible in any (random) order. Most of the memory in a PC is RAM. (2)
See Rambus Dynamic RAM.
To renew a product activation, required when the activation program discovers significant changes in a computer or the activated product has been installed on a second computer. (9)
A reading and writing device in a floppy or hard drive that is mounted on an articulated arm that moves back and forth over the floppy disk or metal platter. (1)
read-only memory (ROM)
Memory that can only be read and that contains program code. ROM is also called firmware. (2)
real-time clock (RTC)
A chip that keeps track of the date and time on a PC. Set the date and time through your operating system or in the BIOS Setup program. (4)
recently used programs list
An area under the pinned items list on the Windows XP Start menu that contains shortcuts to recently run programs. (8)
redundant array of independent disks (RAID)
A group of schemes designed to provide either better performance or improved data reliability through redundancy. (2)
A CRT video setting, also known as the vertical refresh rate, that controls the rate per second at which an image appears on the tube. (3)
Operating system interface settings, such as the language used and the date, time, and currency formats. (9)
Memory locations within a CPU that is used as a scratch pad for calculations. Modern CPUs have dedicated registers for specific functions and general-purpose registers for multiple purposes. (1)
registered jack (RJ)
A rectangular connector with a locking clip on one side and a number designation that refers to the size rather than the number of wires. (3)
The process of informing the software manufacturer who the official owner or user of the product is, and providing contact information such as name, address, company, phone number, e-mail address, and so on, about them. Registration is usually a voluntary action. (9)
A database of all configuration settings in Windows. (8)
In the Windows registry, a folder that may contain one or more sets of settings as well as other keys. (8)
Reliability and Performance Monitor
The Windows Vista and Windows 7 tool for gathering and viewing performance data involving memory, disks, processors, network, and other objectives. (11)
A Windows service designed to allow a user to invite someone to help troubleshoot a problem. (11)
A Windows service that allows a user to connect remotely to a computer and run the Windows desktop on the remote computer, but have the same access as if logged on to the computer and its local network. (11)
Remote Desktop Protocol (RDP)
An underlying protocol that supports Microsoft Remote Desktop. (11)
remote KVM switch
A type of KVM switch that controls computers over a distance that is a function of the cabling and protocols it uses. The two types of switches are local remote KVM switch and KVM over IP. (3)
Storage media that is removable, meaning the drive stays in place, while the media (disk, disc, or tape) is removed and replaced with another disk, disc, or tape. (2)
A network device that is used to extend the range of a network by taking the signals received on a port from one network and regenerating (repeating) those signals to another port to transmit them on a second network. (13)
An LCD display characteristic that indicates the amount of time in milliseconds (ms) it takes for a single pixel to go from the active to the inactive state and back again. (3)
Return To OS Choices menu
An Advanced Options menu choice that appears under certain circumstances. When available, selecting this option will return to the OS Choices menu (OS Loader menu). (11)
See radio frequency.
Radio frequency interference. Radio signals that occur in proximity to equipment that is sensitive to these types of signals. (15)
A simple type of component video signal that sends three separate signals—red, green, and blue—using three coaxial cables. (3)
See RAMBUS Inline Memory Module.
See routing information protocol.
In a low-profile PC case, a card that plugs into a motherboard to allow other cards to be inserted at a right angle to the riser card and parallel to the motherboard. Also, a single expansion card containing multiple functions, such as modem, sound, and network. (1)
A connector that contains two to four wires and usually attaches phone cables to modems and to wall-mounted phone jacks. (3)
A connector that is slightly larger than an RJ-11 connector and contains eight wires. RJ-45 connectors most commonly attach twisted-pair cables to Ethernet network cards. (3)
See read-only memory.
In the FAT file system, the top-level directory in which the operating system stores information about files, including a reference to the FAT table so it knows where to find the file's contents on disk. The NTFS file system also has a root, or top-level directory, but NTFS does not rely on this structure in the same way that FAT does. (10)
The top-level folder or directory in the file structure. This appears the same, regardless of the underlying file system. (10)
In the Windows registry, the top five folders, each of which is the top of a hierarchical structure. Also called subtrees. (8)
Malware that hides itself from detection by antimalware programs; it is installed on a computer by someone who has privileged access to the computer. (16)
A device that sits at the connection between networks and routes packets based on their logical destination addresses. (13)
routing information protocol (RIP)
A protocol that allows routers to update their list of routes dynamically. RIP dates to the 1980s and is considered obsolete; even though, it has been updated a few times and is still supported by most routers. (13)
The classic PC serial port that complies with the Recommended Standard-232 (RS-232) in its circuitry, cabling, and connector design, and transfers data one bit at a time. (3)
Sony-Philips digital interface format—a single-pin RCA phone jack used for transferring digital audio from CD and DVD players to amplifiers and speakers. (3)
See Sony/Philips Digital Interface.
In Windows, an Advanced Options menu choice that starts Windows without several drivers and components and loads only very basic, non-vendor-specific drivers for mouse, video, keyboard, mass storage, and system services. Safe Mode also displays in low resolution. (11)
Safe Mode With Command Prompt
In Windows, an Advanced Options menu choice that will start Windows without the Windows GUI (EXPLORER.EXE) and with only a simple Command Prompt window from which you can launch Windows administrative utilities. (11)
Safe Mode With Networking
In Windows, an Advanced Options menu choice that starts Windows without several drivers and components and loads only very basic, non-vendor-specific drivers for mouse, video, keyboard, mass storage, and system services. It also displays in low resolution. The difference between Safe Mode and Safe Mode With Networking is that the latter will launch networking components. (11)
See Serial Attached SCSI.
See serial ATA.
A communications system now used for data communications via satellite that usually uses microwave radio frequencies and requires a dish antenna, receiver, and transmitter. (13)
Scalable Link Interface (SLI)
A multi-GPU solution developed by NVIDIA. (3)
See Small Computer System Interface.
See SCSI host adapter.
SCSI host adapter
A computer circuit board that attaches to and controls SCSI devices. (4)
A number that identifies a device on a SCSI chain. (4)
See Secure Digital (SD) Card.
See synchronous dynamic RAM.
In reference to IDE PATA drives, the master drive on the second channel. (4)
In reference to IDE PATA drives, the slave drive on the second channel. (4)
second-level domain (SLD)
In the domain name system, a name that is registered under a top-level domain, such as mcgraw-hill.com or microsoft.com. (15)
An early method for addressing the disparity between the drive geometry supported by PC BIOSs and the physical geometry of drives. (1)
secure attention sequence (SAS)
An action, such as the CTRL-ALT-DELETE key combination or the insertion of a smart card, that clears memory of certain types of viruses before a user logs on. (17)
Secure Digital (SD) Card
A solid-state storage standard for high-capacity (2, 4, and 8 GB) memory cards that are tiny—32 mm × 24 mm × 2.1 mm—and support high-speed data transfer. SD cards are in portable devices, such as digital video recorders, digital cameras, handheld computers, audio players, and cell phones. (2)
secure socket layer (SSL)
A data encryption technology used for securing data transmitted over the Internet. (13)
A way to monitor security-related events. (16)
A set of rules and practices describing how an organization protects and manages sensitive information. A security policy applies to all employees. (16)
serial ATA (SATA)
A drive interface for EIDE drives that transfers data serially at speeds between 150 MBps and 300 MBps and 6 Gbps, depending on the version of the standard. (1)
Serial Attached SCSI (SAS)
A marriage of SCSI and Serial ATA, this uses a serial interface to a SCSI bus. (3)
A dedicated computer that stores data and provides print services or other capabilities to network clients. (13)
A bundle of patches or updates released periodically by a software publisher. (8)
Service Set ID (SSID)
A network name used to identify a wireless network. Consisting of up to 32 characters, the SSID travels with the messages on the wireless network. All of the wireless devices on a WLAN must use the same SSID in order to communicate. (14)
Synchronous graphics random access memory is a type of RAM used on video adapters. (2)
A metal plate behind the front of a CRT monitor that focuses the electron beams from the gun. (3)
On a Microsoft Windows network, a resource, such as a file folder or printer, that is available on the network. (15)
shared video memory
A portion of system memory used by a video adapter built into a motherboard. (6)
An icon that represents a link to any object that an icon can represent. Activating a shortcut (by double-clicking it) is a quick way to access an object or to launch a program from the desktop without having to find the actual location of the object on your computer. (8)
In Windows Vista, a vertical bar found by default on the right side of the desktop. Here, you will find gadgets and mini-programs. (8)
See single inline memory module.
Simple Mail Transfer Protocol (SMTP)
A protocol that transfers e-mail messages between mail servers. Clients also use this protocol to send e-mail to mail servers. (13)
simultaneous multithreading (SMT)
See hyper threading.
single inline memory module (SIMM)
An obsolete memory module standard that was produced in 30-pin and 72-pin sizes. Thirty-pin SIMMs are 8-bit, and 72-pin SIMMs are 32-bit. (1)
Pertaining to a DVD drive or disc that can store data in a single layer of pits on each data side. (1)
single-mode fiber (SMF)
Fiber-optic cable that allows only a single light wave to pass down the cable. (13)
single-sided (SS) DVD
A DVD of any type that can contain data on only one side. (1)
The role of the second EIDE drive on a PATA channel. (4)
See second-level domain.
See Scalable Link Interface.
A metal strip used to cover an empty slot in order to preserve the correct air flow and keep dust out. (3)
Small Computer System Interface (SCSI)
An interface standard developed by the American National Standards Institute (ANSI), it is used for both internal and external hard drives and optical drives as well as devices such as printers, modems, scanners, and many other peripherals. (3)
Small Outline DIMM (SODIMM)
A type of DIMM memory module used in laptops. (6)
Small Outline RIMM (SORIMM)
A type of RIMM memory module used in laptops. (6)
A plastic card, often the size of a credit card, that contains a microchip. The microchip can store information and perform functions, depending on the type of smart card. Some smart cards only store data, whereas others may have a variety of functions, including security cards for facilities or logging on to computers. (16)
smart card reader
A device used to scan smart cards. (16)
A cell phone with Personal Digital Assistant (PDA) functions built in. (6)
See Simple Mail Transfer Protocol.
A variety of persuasion techniques used for many purposes—good and bad. People with malicious intent use social engineering to persuade someone to reveal confidential information or give something else of value to the perpetrator. (16)
The location where a cable attaches to a computer. Alternatively, a connector on a motherboard for memory, CPUs, power, or other circuitry. (3)
A service of the operating system on a laptop that detects when a card has been inserted. (6)
See Small Outline DIMM.
A power supply and motherboard feature that allows software to turn off a computer rather than only using a physical switch. (3)
A firewall consisting of software that you can install on any computer, as opposed to the software built into a hardware firewall. Also called personal firewalls because they are designed to be installed on individual desktop computers. (16)
A type of printer that uses solid, rather than liquid, ink. (12)
solid-state drive (SSD)
See solid-state storage.
Data storage technology with no moving mechanical parts that uses large-capacity, nonvolatile memory, commonly calledflash memory or solid-state drives. (2)
A long-established fiber-optic WAN technology. (13)
Sony/Philips Digital Interface (S/PDIF)
A single-pin RCA phone jack for transferring digital audio from CD and DVD players to amplifiers and speakers. (3)
See Small Outline RIMM.
A portion of a computer's chipset that controls communications between the CPU and such I/O busses as USB, IDE, PS2, SATA, and others. (1)
Unsolicited e-mail. (16)
Spam over Instant Messaging (spim)
Unsolicited messages sent over an instant messaging service, such as Windows Messenger. (16)
Speaker On/Off key
A key on a laptop that is combined with the FN key to toggle the laptop's speaker on and off. The SPEAKER ON/OFF key is usually one of the standard function keys, such as F3, that displays a speaker symbol. (7)
Speaker Volume Key
A key on a laptop that is combined with the FN key to bring up a small volume control panel on the display. Using the up (↑) or right (→) arrow key, the volume will increase. To decrease the volume, press the FN key and the SPEAKER VOLUME key along with either the left (←) or down (↓) arrow key. This changes the speaker volume at the hardware level, bypassing Windows' volume control. (7)
One of several groups that no user can create or modify. The membership of a special group is predefined, and it is available to you only when you assign permissions or rights. A few important special groups are Creator Owner, System, and Everyone. (16)
SPGA (staggered pin grid array)
An arrangement of pins on a processor in which the pins are offset in a way that allows for a higher pin density than PGA. (4)
See Spam over Instant Messaging.
In a disk drive, the rotating shaft used to spin the disks. (1)
A category of software that runs surreptitiously on a user's computer in order to gather information without the user's permission and then sends that information to the people who requested it. (16)
See Static RAM.
See secure socket layer.
A computer that is not connected to a network of any kind. (13)
A sleep mode that is available on any computer that supports ACPI power management. It conserves power while saving the desktop in RAM memory in a work state. To resume, you simply press the power button, and the desktop is quickly displayed. (6)
A menu that opens from the Start button on the taskbar. (8)
Start Windows Normally
An Advanced Options menu choice that simply causes Windows to restart normally (if it can). (11)
Static RAM (SRAM)
The first type of RAM available. It is very fast, compared to DRAM, but also very expensive. (2)
status light indicator
One or more lights (usually LEDs) on a device that indicate the device's operational status through the color of the light, by blinking or remaining steady or both. (5)
straight-tip (ST) connector
A straight, round connector used to connect fiber-optic cabling to a network device. It has a twist-type coupling. (13)
striping with distributed parity
See RAID 5.
striping with interleave parity
See RAID 5.
A password that meets certain criteria in order to be difficult to crack. One definition of a strong password is one that contains at least eight characters, includes a combination of letters, numbers, and other symbols ( _, -, $, and so on) and is easy for you to remember but difficult for others to guess. (16)
See lit pixel.
The primary input device for a PDA, shaped like a pen and used to press small keys on a keypad, tap the screen to select items, or write data on the screen. (6)
A registry key that exists within another key. (8)
sub-mini audio connector
A 3/32" audio connector. (3)
subscriber connector (SC)
A square snap coupling for fiber-optic cable, about 2.5 mm wide, used for cable-to-cable connections or to connect cables to network devices. It latches with a push-pull action similar to audio and video jacks. (13)
subscription channel (SC)
A paid television subscription service offered by cable television providers. (13)
See root key.
super video graphics array (SVGA)
Any video adapter or monitor that exceeds the VGA standard in resolution and color depth with a maximum resolution of 1600 × 1200. (3)
A device, usually resembling a power strip, that protects equipment from power surges. (5)
See surge protector.
See super video graphics array.
A video interface, also called Super Video, that transmits video using two signals—luminance, represented by a Y, and chrominance, represented by a C. S-video ports are round to accommodate a round plug with four pins. (3)
See paging file.
 On computer circuit boards, a very tiny slide that indicates two states. (4).  In a network, a network device, much like a hub, except that a switch takes an incoming signal and sends it to only the destination port, avoiding collisions and making it more efficient than a hub. (13)
switching mode power supply
A power supply that converts between alternating current and direct current. (3)
Super XGA, a video graphics mode with a maximum resolution of 1280 × 1024. (3)
synchronous dynamic RAM
DRAM that runs at the speed of the system bus (up to 100-133 MHz). (2)
The area at the beginning of a disk formatted with the FAT file system. This area contains the boot record, FAT table, and root directory. (10)
A file attribute assigned to a file by the operating system to identify it as a system file. (10)
See expansion bus.
System Configuration Utility
A program file or some special data file that is part of the operating system and is very important to proper operation of the OS. (10)
System File Checker (SFC)
A Windows command prompt utility that uses the WFP (Windows 2000 and Windows XP) or WRP (Windows Vista and Windows 7) service to scan and verify the versions of all protected system files after you restart your computer. (11)
System Information (MSINFO32.EXE)
This GUI utility will display a system summary of the hardware, operating system, and other software. (11)
System Management Mode (SMM)
A CPU power-saving mode that allows a CPU to reduce its speed without losing its place so it does not stop working altogether. SMM also allows the CPU to trigger power saving in other components. (6)
A utility in Windows XP and Windows 2000 for gathering and viewing performance data involving memory, disks, processors, networks, and other objectives. (11)
The specific requirements for the level of CPU, amount of memory, and size of the hard disk for the computer on which an operating system can be installed. (8)
A finite set of resources controlled by the operating system and critical to the use of all computer components. (5)
An operating system recovery tool introduced in Windows Me and improved in later versions of Windows. System Restore creates restore points, which are snapshots of Windows, its configuration, and all installed programs. If your computer has nonfatal problems after you have made a change, you can use System Restore to roll it back to a restore point. (11)
An area of the Windows taskbar used by programs and some hardware devices to display status icons. Also called thenotification area or system tray. (8)
A level of service offered by the telephone companies over a T-carrier circuit that provides full-duplex transmissions at 1.544 Mbps, carrying digital voice, data, or video signals. (13)
A laptop in which the display is an integrated digitizer. (6)
Showing consideration for others. (18)
A magnetic mass storage device primarily used for backing up data from computers. (1)
A Windows utility that allows you to create tasks that run automatically at the times you select. (11)
In the Windows GUI, a horizontal bar normally positioned across the bottom of the desktop containing a Start button, the Quick Launch toolbar, buttons for running programs, and at the far right, the notification area. Sometimes called the Start Bar. (8)
A communications system, owned and operated by the telephone companies, that multiplexes voice and data signals onto digital transmission line. (13)
A network protocol suite originally developed for the Internet; it has been mostly adopted on private networks. (13)
A utility that provides remote terminal emulation for connecting to computers and network devices running server software that can respond, without needing to be concerned with the actual operating system running on either system. (13)
Temporal Key Integrity Protocol (TKIP)
A protocol used with WPA wireless encryption that was broken by hackers. (16)
At first, a terminal was not much more than a display, a keyboard, and the minimal circuitry for connecting to the mainframe. Now, a terminal can be a computer running Windows or other operating system, plus terminal client emulation software that allows it to connect to a server in which a separate session is run for the client computer. (13)
A device installed at the end of a SCSI chain to absorb signals so they do not bounce back along the cable. (4)
A special substance, also called thermal paste or heat sink compound, that increases the heat conductivity between a fan or heat sink and a chip. (3)
See thermal compound.
A type of printer that uses heat in the image transfer process. (12)
thermal wax transfer printer
A type of printer that uses a film coated with colored wax that melts onto paper. These printers are similar to dye-sublimation printers but differ in two major ways: the film contains wax rather than dye, and these printers do not require special paper. (12)
thin-film transistor (TFT)
A technology for LCD displays in which transistors are positioned at each pixel. (3)
A portion of a program that can run separately from and concurrently with other portions of the program. Also called thread of execution. (1)
thread of execution
A type of solid-state storage that is portable, about the size of a flattened thumb, and usually has a USB interface. Also called a flash drive or jump drive. (2)
time to live (TTL)
In an IP packet, a value field that shows how many routers the packet can cross before being discarded. (15)
See top-level domain.
The medium for a laser printer, which is normally packaged within a toner cartridge. (12)
The cartridge for a laser printer that contains both the medium (toner) and other printing components. (12)
top-level domain (TLD)
In the domain name system, a first-level domain, which is a suffix added to a registered domain name and separated from the domain name with a "dot" (.). Among the TLDs are .com, .gov, .edu, .org, .mil, .net, .biz, many two-lettered country codes, and several others. (15)
A type of display device that includes a touch-sensitive face to accept input from the user. (3)
A pointing device, often built into a laptop, which is a smooth rectangular panel over which you move your finger to move the pointer on the display. (6)
A command-line utility, installed with the TCP/IP protocol suite, that traces the route taken by packets to a destination. (15)
The fine copper lines that are the electronic circuits through which power, data, and control signals travel on a circuit board. (1)
The generic term for a pointing stick. (6)
The IBM branded name for a pointing stick or track point. (6)
transfer corona wire
In the laser printing process, a wire that passes a small positive charge to paper as it travels through the printer. This positive charge attracts the negatively charged toner particles on the drum to the paper. (12)
In the laser printing process, the step in which the toner on the drum is transferred to the paper. (12)
Transmission Control Protocol (TCP)
One of the two main protocols of the TCP/IP protocol suite, TCP breaks the data into chunks, called datagrams. Each datagram also contains information, stored in a header, which is used by the TCP protocol on the receiving end to reassemble the chunks of data into the original message. (13)
transport layer security (TLS)
A data encryption technology used for securing data transmitted over the Internet. TLS succeeded SSL. (13)
A virus that gains access to a computer by masquerading as a harmless program that a user innocently installs on the computer. (16)
The act of discovering the cause of a problem and correcting it. (5)
trusted platform module (TPM)
A TPM is a special microchip, installed on a motherboard, that stores passwords, keys, and digital certificates. Various services, such as BitLocker can store such security data in this chip. (16)
See time to live.
TV tuner card
See capture card.
A set of standards for imaging devices, such as scanners and cameras, that is used in drivers and other software for these devices. (12)
Cable that consists of pairs of wires twisted around each other. The twists help to boost each wire's signals and make them less susceptible to electromagnetic interference (EMI). (3)
A card that fits into the PC Card interface, including both PC Card and CardBus cards. This type measures 85.6 millimeters long by 54 millimeters wide and 3.3 millimeters thick. (6)
A card that fits into the PC Card interface, including both PC Card and CardBus cards. This type measures 85.6 millimeters long by 54 millimeters wide and 5.0 millimeters thick. (6)
A card that fits into the PC Card interface, including both PC Card and CardBus cards. This type measures 85.6 millimeters long by 54 millimeters wide and measures 10.5 mm thick. (6)
See uniqueness database file.
Ultra DMA (UDMA)
A technology used by hard drives to speed up data transfers by using DMA channels. (1)
The smallest laptop type, weighing less than 3 pounds. See also netbook and mini-notebook. (6)
An automated software installation that does not require a person be present to respond to prompts for information. (9)
In reference to parallel ports, a mode in which the parallel device connected to the parallel port can receive data but cannot send data. CMOS settings (system settings) may refer to this mode as "Transfer only." (4)
uninterruptible power supply (UPS)
An online power protection device that isolates a computer or other device plugged into it. During normal operation, the devices run directly off the battery through an inverter, rather than switching to the battery only after a loss of power. (5)
uniqueness database file (UDF)
A file used with a scripted unattended installation along with an answer file. The UDF file provides settings that are unique for each computer. (9)
universal asynchronous receiver/transmitter (UART)
A chip that works with a serial port, converting outgoing data from parallel to serial and incoming data from serial to parallel. (3)
universal data format (UDF)
A file format for movie DVDs. (10)
Universal Serial Bus (USB)
An external bus that connects into the PC's PCI bus. With USB, you can theoretically connect up to 127 devices to your computer. (3)
In Microsoft terminology, software that contains one or more software fixes or changes to the operating system. (8)
See uninterruptible power supply.
See Universal Serial Bus.
User Account Control (UAC)
A security feature introduced in Windows Vista to prevent unauthorized changes to Windows. (8)
User Datagram Protocol (UDP)
A subprotocol of TCP/IP used for connectionless communications in which each packet is sent without establishing a connection. (13)
User State Migration Tool (USMT)
A utility for migrating data from many computers, or if you need to perform what Microsoft calls a "wipe-and-load migration" from and to the same computer. Available in Windows XP, Vista, and Windows 7. (9)
Ultra extended graphics array, a video graphics mode with a maximum resolution of 1600 × 1200. (3)
The settings within a registry key. (8)
See virtual circuit.
A new level of an operating system with major changes to the core components. (8)
An LCD display setting that adjusts the viewable area of the display vertically. (3)
vertical refresh rate
See refresh rate.
See Video Electronics Standards Organization.
See virtual file allocation table.
See video graphics array.
A video mode that most often consists of a combination of 640 × 480 pixels display resolution and 16 colors. VGA can produce around 16 million different colors, but can display only up to 256 different colors at a time. (3)
A CRT video setting, also known as vertical hold, that holds the image vertically on the screen. (3)
Circuitry in a PC on an adapter card, or directly on the motherboard, that controls the output from the PC to the display device. (3)
video adapter card
A circuit card in a PC that controls the output to the display device(s). (2)
Video Electronics Standards Organization (VESA)
An organization that created several PC standards, including the VGA connector. (3)
video graphics array (VGA)
An obsolete video standard introduced with IBM PS/2 computers in the late 1980s. VGA had a maximum resolution of 720 × 400 in text mode and 640 × 480 in graphics mode. (3)
video RAM (VRAM)
A specialized type of memory used only with video adapters. (2)
virtual circuit (VC) A
communication service provided over a telecommunications network or computer network. A VC logically resembles a circuit while passing over a complex routed or switched network, such as the phone company's frame relay network. (13)
virtual file allocation table (VFAT)
A modified version of FAT12 and FAT16 used in Windows since Windows 95. (10)
The use by the operating system of a portion of hard disk as memory. (9)
virtual private network (VPN)
A virtual tunnel created between two endpoints over an untrusted network. The tunnel is created by encapsulating the packets within special packets for the tunnel. Other security methods are also usually applied to a VPN, such as encrypting the data before encapsulating it, along with encrypted authentication. (13)
A program installed and activated on a computer without the user's knowledge or permission. At the least, the intent is mischief, but most often the intent is to cause damage. (16)
A generic term for a collection of information on known malware (not just viruses). (17)
Voice over IP (VoIP)
A set of technologies that allow voice transmission over an IP network—specifically used for placing phone calls over the Internet—rather than the public switched telephone network (PSTN), the worldwide network that carries traditional voice traffic. (13)
See Voice over IP (VoIP).
A word used to describe memory that cannot work without a steady supply of power. (2)
voltage regulator module (VRM)
A circuit on a motherboard through which incoming power passes. Several voltage regulators maintain a steady voltage as demand goes up and down, with one or more voltage regulators for the various voltages required (5 volts, 12 volts, 3.3 volts, etc.). (1)
A measurement of the pressure of electrons, the electromotive force. It is calculated by the formula volts = watts / amps. (3)
The term used for dynamic space allocation that can be formatted with a file system. (10)
See video RAM.
A connection over a wide area network. (13)
See wireless access point.
A mark on a building created by a war driver to specify where a hotspot exists. People "in the know" look for these marks to identify hotspots for their use. (16)
The act of moving through a neighborhood in a vehicle or on foot, using either a laptop equipped with Wi-Fi wireless network capability or a simple Wi-Fi sensor available for a few dollars from many sources. War drivers are searching for open hotspots—areas where a Wi-Fi network connects to the Internet without using security to keep out intruders. (16)
A unit of measurement of actual delivered power, calculated by the formula watts = volts × amps. (3)
Client software for browsing and accessing the content on the World Wide Web. Examples include Internet Explorer and Firefox. (14)
See Wired Equivalent Privacy.
wide area network (WAN)
A network connection over long distances, traditionally using phone lines or satellite communications. (13)
See Wireless Fidelity.
Wi-Fi Protected Access (WPA)
A wireless data encryption standard based on the IEEE 802.11i security standard. It issues keys per-user and per-session and includes encryption key integrity checking. It uses Temporal Key Integrity Protocol (TKIP). (16)
Wi-Fi Protected Access 2 (WPA2)
An improved version of WPA that does not support older network cards and offers both secure authentication and data encryption. It uses EAP for a variety of authentication methods—most often EAP-PSK. (16)
Windows Easy Transfer (WET)
The utility to use when doing a single data and settings transfer to a new Windows Vista computer from one running Windows XP or Windows Vista. (9)
The EXPLORER.EXE program. This program supports the entire Windows GUI. If EXPLORER.EXE is called up from inside the GUI, it opens a window for browsing your local disks and files. (8)
Windows Internet Naming Service (WINS)
A service that manages Microsoft NetBIOS names for a Windows network. This service is becoming obsolete, as Windows has moved to DNS for naming and name service. (13)
A Windows program that launches Internet Explorer and connects to the Windows Update Website. (9)
Windows Update Website
The Microsoft Website from which you can download updates to Windows. (9)
Windows XP Files and Settings Transfer Wizard
A tool for migrating user data and settings from one Windows computer to a computer running Windows XP. (9)
See Windows Internet Naming Service.
A Windows server running the WINS service to maintain and resolve NetBIOS names. (13)
Wired Equivalent Privacy (WEP)
The oldest of the Wi-Fi encryption standards. It uses 64- or 128-bit encryption that is easily broken. It does not encrypt the actual data in a packet, and it does not perform user authentication on a packet. (16)
wireless access point (WAP)
A network connection device at the core of a wireless network. (13)
Wireless Fidelity (Wi-Fi)
Local area networking using radio waves that includes several implementations based on the IEEE 802.11 group of standards. (13)
Wireless LAN (WLAN)
Local area networking using radio waves, with the most common based on the IEEE 802.11 group of standards (802.11a, 802.11b, 802.11g, and 802.11n). (13)
A term used by Microsoft for a peer-to-peer network in which each computer can be either a client or a server or both. (13)
World Wide Web
The graphical Internet consisting of a vast array of documents located on millions of specialized servers worldwide. The documents are created using HTML and other specialized languages, and transferred from servers to client computers using HTTP and related transport protocols. Client software for the World Wide Web is called a Web browser. (13)
A virus that is self-replicating. (16)
See Wi-Fi Protected Access (WPA).
See Wi-Fi Protected Access 2.
Video RAM memory that uses a technique for using video RAM to perform Windows-specific functions to speed up the OS. (2)
In the laser printing process, the step in which the laser beam creates a negative of the image that will eventually appear on the printout. Each place that the laser beam touches loses most of its charge, creating an image, whereas the rest of the drum remains highly negatively charged. (12)
Wide-ultra-extended graphics array—a widescreen video graphics mode with a maximum resolution of 1920 × 1200. (3)
See World Wide Web.
A term applied to a CPU, motherboard, or other components that conform to the Intel 32-bit x86 specification. Also referred to as 32-bit. (5)
A term applied to a CPU, motherboard, or other components that conform to the newer 64-bit architecture. Also referred to as 64-bit. (5)
A video mode with a maximum graphics resolution of 1024 × 768. (3)
Used to represent the luminance signal in S-Video. (3)
zero insertion force (ZIF) socket
A socket for a PGA CPU that has a retention lever as well as contacts to match the number of pins on the CPU. The lever is used to attach the CPU to the socket in a manner that does not require force to insert or to remove the CPU. (1)
See zero insertion force (ZIF) socket.