Part of the CPU that performs arithmetic operations and logical operations and controls the speed of those operations.
ASCII (American Standard Code for Information Interchange)
Binary code used on microcomputers. Besides having more conventional characters, the Extended ASCII version includes such characters as math symbols and Greek letters.
A two-state system used for data representation in computers; has only two digits - 0 and 1.
Short for "binary digit," which is either a 0 or a 1 in the binary system of data representation in computer systems.
Wireless technology that consists of short-range radio waves that transmit up to 30 feet.
Optical format developed to enable recording, rewriting, and playback of high-definition video, as well as storing large amounts of data.
Also called bus line; electrical data roadway through which bits are transmitted within the CPU and between the CPU and other components of the motherboard.
Group of 8 bits.
Special high-speed memory area on a chip that the CPU can access quickly. It temporarily stores instructions and data that the processor is likely to use frequently.
CD-R (Compact Disk-Recordable)
Optical-disk form of secondary storage that can be written to only once but can be read many times.
CD-ROM (Compact Disk Read-Only Memory)
Optical-disk form of secondary storage that is used to hold prerecorded text, graphics, and sound.
CD-RW (Compact Disk Rewritable) Disk
Also known as erasable optical disk; optical-disk form of secondary storage that allows users to record and erase data, so the disk can be used over and over again. Special CD-RW drives and software are required.
Also called a microchip; consists of millions of microminiature integrated electronic circuits printed on a tiny piece of silicon. Silicon is an element widely found in sand that has desirable electrical (or "semiconducting") properties.
Groups of interconnected chips on the motherboard that control the flow of information between the microprocessor and other system components connected to the motherboard.
Online storage; the use of an Internet service to store data.
CMOS (Complementary Metal-Oxide Semiconductor)
Battery-powered chips that don't lose their contents when the power is turned off.
Part of the CPU that deciphers each instruction stored in it and then carries out the instruction.
CPU (Central Processing Unit)
The processor; it follows the instructions of the software (program) to manipulate data into information. The CPU consists of two parts - (1) the control unit and (2) the arithmetic/logic unit (ALU), both of which contain registers, or high-speed storage areas. All are linked by a kind of electronic "roadway" called a bus.
Sometimes called a server farm; a facility that holds servers and related network equipment .
DVD-ROM (Digital Versatile Disk or Digital Video Disk, With Read Only Memory)
CD-type disk with extremely high capacity, able to store 4.7-17 or more gigabytes.
SATA stands for Serial Advanced Technology Attachment. An eSATA port, or external SATA port , allows the attachment of an eSATA hard disk.
Network standard for linking all devices in a local area network (LAN).
Approximately 1 quintillion bytes - 1 billion billion bytes.
Way of increasing a computer's capabilities by adding hardware to perform tasks that are beyond the scope of the basic system.
Also known as an expansion board, adapter card, interface card, plug-in board, controller card, add-in or add-on; circuit board that provides more memory or that controls peripheral devices.
Socket on the motherboard into which the user can plug an expansion card.
A specialized port intended to connect devices working with lots of data.
Flash Drive/USB Flash Drive
Also called a thumb drive, keychain drive, flash drive, or key drive; a finger-sized module of flash memory that plugs into the USB ports of nearly an PC or Macintosh, as well as many electronic devices.
Flash Memory Card
Also known as flash RAM cards; form of secondary storage consisting of circuitry on credit-card-size cards that can be inserted into slots connecting to the motherboard on notebook computers.
Flash Memory Chip
Chip that can be erased and reprogrammed more than once (unlike PROM chips, which can be programmed only once).
Flash Memory Stick
Smaller than a stick of chewing gum, a form of flash memory media that plugs into a memory stick port in a digital camera, camcorder, notebook PC, photo printer, and other devices.
Gigabyte (G, GB)
Approximately 1 billion bytes; a measure of storage capacity.
Measure of speed used for the latest generation of microprocessors: 1 billion cycles per second.
Also called a video card, video RAM (VRAM), or video adapter; expansion card that converts signals from the computer into video signals that are displayed as images on a monitor.
Graphics Processing Unit (GPU)
Specialized processor used to manipulate three-dimensional computer graphics.
Secondary-storage medium; thin but rigid metal, glass, or ceramic platter covered with a substance that allows data to be stored in the form of magnetized spots. Hard disks are tightly sealed within an enclosed hard-disk-drive unit to prevent any foreign matter from getting inside. data may be recorded on both sides of the disk platter.
HDMI (High-Definition Multimedia Interface) Port
Multimedia connection that can carry both video and audio signals.
A set of electronic circuits, including wires, formed (etched) on a single "chip," or piece, of special material, usually silicon. An integrated circuit is formed as part of a single manufacturing process.
Processor chip originally made for microcomputers; made principally by Intel Corp. and Advanced Micro Devices (AMD), but also by Cyrix, DEC, and others.
Short for Infrared Data Association.
Kilobyte (K, KB)
Approximately 1,000 bytes; a measure of storage capacity.
Series of operations performed by the control unit to execute a single program instruction. It (1) fetches an instruction, (2) decodes the instruction, (3) executes the instruction, and (4) stores the result.
Binary code (language) that the computer uses directly . The 0s and 1s represent precise storage locations and operations.
Megabyte (M, MB)
Approximately 1 million bytes; measure of storage capacity.
Measure of microcomputer processing speed, controlled by the system clock; 1 million cycles per second.
Miniaturized circuitry of a computer processor. It stores program instructions that process, or manipulate, data into information. The key parts of the microprocessor are transistors.
Short for Musical Instrument Digital Interface.
Microcomputer chip such as Intel's dual-core, quad-core, hex-core, and octo-core processors, with two or more processor "cores" on a single piece of silicon.
Network Interface Card (NIC)
Expansion card that allows the transmission of data over a cabled (wired) network.
Removable disk, usually 4.75 inches in diameter and about .05 inches thick, on which data is written and read through the use of laser beams.
A connector for a line that allows 8 bits (1 byte) to be transmitted simultaneously, like cars on an eight-lane highway.
Thin, credit-card size flash memory device.
Petabyte (P, PB)
Approximately 1 quadrillion bytes; measure of storage capacity.
Plug and Play
Peripheral connection standard - such as USB and FireWire - that allows peripheral devices and expansion cards to be automatically configured while they are being installed.
A connecting socket or jack on the outside of the system unit into which are plugged different kinds of cables.
Device that converts AC to DC to run the computer.
RAM (Random Access Memory) Chips
Also called primary storage and main memory; chips that temporarily hold software instructions and data before and after it is processed by the CPU. RAM is a volatile form of storage.
To transfer data from an input source into the computer's memory or CPU.
Mechanism used to transfer data between the computer and the hard disk. When the disk spins inside its case, the read/write head moves back and forth over the data access area on the disk.
High-speed storage areas that temporarily store data during processing.
ROM (Read-Only Memory)
Memory chip that cannot be written or erased by the computer user without special equipment.
Devices that permanently hold data and information as well as programs.
The small arcs created in tracks when a disk's storage locations are divided into wedge-shaped sections.
Material, such as silicon, whose electrical properties are intermediate between a good conductor and a nonconductor of electricity. When highly conducting materials are laid on the semiconducting material, an electronic circuit can be created.
A connector for a line that sends bits one after another, like cars on a one-lane highway.
Plastic card that looks like a credit card but has a microprocessor and memory chips embedded in it. When inserted into a reader, it transfers data to and from a central computer.
Electronic component, such as an integrated circuit, made of solid materials with no moving parts.
Storage technology that uses flash memory to store data, instructions, and information. SSD's have a capacity of 16-256 gigabytes and have no moving parts to break down, as disk drives do.
Expansion card used to convert and transfer digital sounds through analog speakers, microphones, and headsets.
Internal timing device that uses fixed vibrations from a quartz crystal to deliver a steady stream of digital pulses or "ticks" to the CPU. These ticks are called cycles.
The metal or plastic case that houses a computer's electronic components used to process data.
Wireless, portable personal computer with a touch-screen interface. Tablets are typically smaller than notebooks but larger than smartphones.
Terabyte (T, TB)
Approximately 1 trillion bytes; measure of storage capacity.
The rings on a hard disk along which data is recorded.
Tiny electronic device that acts as an on/off switch, switching between "on" and "off" millions of times per second.
Binary coding scheme that uses 2 bytes for each character, rather than 1 byte.
Changing to newer, usually more powerful or sophisticated versions, such as a more powerful microprocessor or more memory chips.
USB (Universal Serial Bus) Port
High-speed hardware standard for interfacing peripheral devices, such as scanners and printers, to computers without a need for special expansion cards or other hardware modifications to the computer.
Type of hard-disk space that is used to extend RAM capacity.
Temporary; the contents of volatile storage media, such as RAM, are lost when the power is turned off.
Wireless Network Card
An expansion card that supports networking.
Number of bits that the processor may process at any one time.
To transfer data from the computer's CPU or memory to an output device.