a data communications network that connects personal computers within a very limited geographical area- usually a single building. __s use a variety of wired and wireless technologies. Ex: school comp labs, home networks
WAN (wide area network)
covers a large geographical area and usually consists of several smaller networks, which might use different computer platforms and network technologies. Internet is the world's largest __. Ex: networks for nationwide banks, large cable tv companies, multi-location superstores
MAN (metropolitan area network)
public high-speed network capable of voice and data transmission within a range of about 50 miles. Ex: local internet service providers, small cable tv companies, local telephone companies.
networks that include one or more servers can operate in ___ mode. ___ is a computer that provides services to other computers called ___.
any electric device that broadcasts network data, boosts signals, or routes data to its destination. Ex: hubs, switches, routers, gateways, bridges, repeaters.
connects all devices in a circle, with each device having exactly two neighbors. Data is transmitted from one device to another around the ___. This topology minimizes cabling, but failure of any one device can take down the entire network
central connection point that links cables or handles wireless broadcasts to all workstations and peripherals. Many home networks arranged in star.
connects each network device to many other network devices. Data traveling on a mesh network can take any of several possible paths from its source to its destination. Even if several links fail, data can follow alternative functioning links to reach its destination. Original Internet plan was based on ___. ___ used for some wireless networks.
high bandwidth communications systems, such as cable TV and DSL. Essential for networks that support many users, as well as for those that carry lots of audio and video data, such as music and movie downloads.
systems with less capacity, such as dial-up internet access.
technology which divides a message into several packets that can be routed independently to their destination.
technology which essentially establishes a dedicated, private link between one telephone and another for the duration of a call. Provides callers with a direct pipeline over which streams of voice data can flow.
Home PNA Network (HPNA)
a network technology that utilizes existing telephone wires and coaxial cables to connect network devices.
uses premises electrical wiring to form the infrastructure for a LAN. Data, transmitted as low frequency radio waves, travels along the electrical wiring from one network device to another at speeds of about 10 Mbps.
i. Advantages- transports data from one device to another w/o wires or cables. Mobility- can be moved from room to room or outdoors. Power spikes are much less likely to run through cables to damage workstations.ii. Disadvantages- In the past more expensive than wired. Speed, range, licensing, security.
i. Advantages- fast, secure, simple to configure. File transfers on wired networks are faster than on wireless. Faster infrastructure for playing multiplayer comp games. ii. Disadvantages- limited mobility, undesired appearance of wires.
scrambles the data transmitted between wireless devices and then unscrambles the data only on devices that have a valid encryption key.
WEP (wired equivalent privacy)
Name b/c it was designed to provide a level of confidentiality similar to that of a wired network. original wireless encryption. 1st version of __ was easy to bypass, second has stronger encryption, but can still be easily exploited by hackers.
WPA (wi-fi protected access)
offers stronger protection by making sure that packets have not been intercepted or tampered with in any way. PSK(pre-shared key) aka personal mode, is a type of ___ used on most home networks. All workstations use the same key to connect to the network. better security than WEP
an original message (one that hasn't been encrypted). Aka cleartext.
an encrypted message
plaintext to ciphertext
ciphertext to plaintext
ARPANET (Advanced Research Projects Agency Network)
the world's first operational packet switching network and the core network of a set that came to compose the global internet.
a company that offers internet access to individuals, businesses, and smaller ___s. Operates routers, communication equipment, and other network decices that handle the physical aspects of transmitting and receiving data between their subscribers and the internet.
converts the signals from your computer into analog signals that can travel over telephone lines.
the primary protocol suite responsible for message transmission on the internet. Protocol suite is a combo of protocols that work together. Provides a protocol standard for the internet that is public, free, extensible, and easy to implement.
TCP (transmission control protocol)
breaks a message or file into packets
responsible for addressing packets so that they can be routed to their destination.
Static IP address
permanently assigned address. Computers on the internet that act as servers, ISPs websites, web hosting services, email servers that always need to be found at the same address.
Dynamic IP Address
temporarily assigned address
private IP address
a non-routable IP address that can be used within a LAN, but not for the internet data transport.
routable IP address
address that can be accessed by packets on the internet.
contains circuitry that converts the data-carrying signals from your computer to signals that can travel over various communications channels. Type of modem you use depends on whether your ISP supplies dial-up, cable, satellite, or DSL internet service.
a fixed internet connection that uses a voiceband modem and telephone lines to transport data between your computer and your ISP.
a means of distributing always-on broadband internet access over the same infrastructure that offers cable television service.
DSL (digital subscriber line)
) high-speed, digital, always-on, internet access technology that runs over standard phone lines. One of the fastest internet connections that is affordable to individual consumers
a means of distributing always-on, high-speed asymmetric internet access by broadcasting signals to and from a personal ___. In some rural areas, this internet is the only alternative to dial-up.
wi-max (worldwide interoperability for microwave access)
an Ethernet-compatible network standard designated as IEEE 802.16. Offers an alternative to wired technologies that require expensive infrastructures
cellular service providers offer data services called
time elapsed for data to make a round trip from point A to point B and back to point A.
FTP (file transfer protocol)
provides a way to transfer files from one computer to another over any TCP/IP network, such as a LAN or the internet
file sharing. Uses peer-to-peer protocols that allow users to obtain files from other users located anywhere on the internet
the use of automated software to locate computers that have open ports and are vulnerable to unauthorized access. Software called a port scanner goes to a randomly selected IP address and systematically checks for a response from each port. Open ports can then be further tested to gauge their suitability for exploitation.
intended to work on LANs to monitor and direct packets being transported from one device to another. Can also connect to the internet through a DSL, cable, or satellite modem.
VPN (virtual private network)
access to a remote server in the corporate office. Secure remote connections by setting one of these up. Access to a ___ is usually invitation only.
client software that displays web page elements and handles links between pages. Main tool for accessing web pages.
HTML (hypertext markup language)
set of specifications for creating documents that a browser can display as a web page.
special instructions that specify how the document should appear when displayed on a computer screen or printed
HTTP (hypertext transfer protocol)
a protocol that works with TCP/IP to get web resources to your desktop. Web resource can be any chunk of data that has a URL, such as an HTML document, a graphic, or a sound file.
software that pulls keywords from a webpage and stores them in a database. Purpose is to make pages easy to find based on their contents.
a computer program that is automated to methodically visit websites. Can be programmed to perform various activities as they visit sites.
looks for your search terms in the search engine's indexed database and returns a list of relevant Web sites. The order in which web sites are listed in response to a search depends on relevancy criteria.
entered into a header section of a web page when it is created and is supposed to describe the page contents.
refers to business transactions that are conducted electronically over a computer network. Encompasses all aspects of business and marketing processes enabled by internet and web technologies.
B2C (business to consumer)
individual consumers purchase goods and services from online merchants
C2C (consumer to consumer)
another popular e-commerce model in which consumers sell to each other at popular online auctions
B2B (business to business)
involves one enterprise buying goods or services from another enterprise
B2G (business to government)
aims to help businesses sell to governments
POP (post office protocol)
temporarily stores new messages on an email server. When you connect to your ISP and request your mail, it is downloaded from the email server and stored on your computer.
SMTP ( simple mail transfer protocol server)
routes outgoing e-mail
Web- mased email
keeps your email at a web site, where it can be accessed using a standard web browser.
or clear GIF is typically a 1x1 pixel graphic embedded in a web page or e-mail message. Almost invisible due to its size, designed to track who's reading the web page or email message.
an exploit that redirects users to fake sites by poisoning a domain name server with a false IP address.
a situation in which one person or program successfully masquerades as another by falsifying data and thereby gaining an illegitimate advantage.
an e-mail based scam that's designed to persuade you to reveal confidential info such as your bank account number or SSN. ___ scams require that you reply to an email message or click an embedded website link for the scam to unfold.
a message sent from a web server to a browser and stored on a user's hard disk, usually containing info about the user.
refers to new and innovative ways of using the web.
refers to the number of times per second that a sound is measured during the recording process. Expressed in hertz. Higher sampling rates increase the quality of the sound recording but require more storage space than sampling rates.
Digital signal processor
performs three important tasks. Transforms digital bits into analog waves when you play a digital audio file; transforms analog waves into digital bits when you make a sound recording; handles compression and decompression, if necessary.
is the ability of a machine to understand spoken words
the process by which machines, such as computers, produce sound that resembles spoken words.
composed of a grid of dots. The color of each dot is stored as a binary number. Created by dividing an image into a grid of pixels.
consists of a set of instructions for re-creating a picture. Contains the instructions the computer needs to create the shape, size, position, and color for each object in an image.
High-res graphics v. low-res graphics
Res of an image indicates the number of dots per inch (dpi). High resolution is clearer and better than low- res graphics. Low res lacks fine detail.
the process of converting a vector graphic into a bitmap graphic. Works by superimposing a grid over a vector image and determining the color for each pixel.
stored as a set of instructions. The instructions contain the locations and lengths of lines that form a wireframe for a _______ object.
DRM (Digital rights management)
a collection of techniques used by copyright holders to limit access to and use of digital content. Usually refers to movies, music, e-books, and comp games.
reduction of the storage space required for data by changing its format.