A B C D E F G H I J K L M N O P Q R S T U V W X Y Z.

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CABLE MODEM: A cable modem is a device that enables you to hook up your PC to a local cable TV line and receive data at about 1.5 Mbps. This data rate far exceeds that of the prevalent 28.8 and 56 Kbps telephone modems and the up to 128 Kbps of ISDN and is about the data rate available to subscribers of Digital Subscriber Line (DSL) telephone service. A cable modem can be added to or integrated with a set-top box that provides your TV set with channels for Internet access. In most cases, cable modems are furnished as part of the cable access service and are not purchased directly and installed by the subscriber.
A cable modem has two connections: one to the cable wall outlet and the other to a PC or to a set-top box for a TV set. Although a cable modem does modulate between analog and digital signals, it is a much more complex device than a telephone modem. It can be an external device or it can be integrated within a computer or set-top box. Typically, the cable modem attaches to a standard 10Base-T Ethernet card in the computer.
All of the cable modems attached to a cable TV company coaxial cable line communicate with a Cable Modem Termination System (CMTS) at the local cable TV company office. All cable modems can receive from and send signals only to the CMTS, but not to other cable modems on the line. Some services have the upstream signals returned by telephone rather than cable, in which case the cable modem is known as a telco-return cable modem.
The actual bandwidth for Internet service over a cable TV line is up to 27 Mbps on the download path to the subscriber with about 2.5 Mbps of bandwidth for interactive responses in the other direction. However, since the local provider may not be connected to the Internet on a line faster than a T-1 at 1.5 Mpbs, a more likely data rate will be close to 1.5 Mpbs.

CGI: The common gateway interface (CGI) is a standard way for a Web server to pass a Web user's request to an application program and to receive data back to forward to the user. When the user requests a Web page (for example, by clicking on a highlighted word or entering a Web site address), the server sends back the requested page. However, when a user fills out a form on a Web page and sends it in, it usually needs to be processed by an application program. The Web server typically passes the form information to a small application program that processes the data and may send back a confirmation message. This method or convention for passing data back and forth between the server and the application is called the common gateway interface (CGI). It is part of the Web's HTTP protocol.
If you are creating a Web site and want a CGI application to get control, you specify the name of the application in the URL that you code in an HTML file. This URL can be specified as part of the FORMS tags if you are creating a form. For example, you might code:
<FORM METHOD=POST ACTION=http://www.mybiz.com/cgi-bin/formprog.pl>
and the server at "mybiz.com" would pass control to the CGI application called "formprog.pl" to record the entered data and return a confirmation message. (The ".pl" indicates a program written in Perl but other languages could have been used.)
The common gateway interface provides a consistent way for data to be passed from the user's request to the application program and back to the user. This means that the person who writes the application program can makes sure it gets used no matter which operating system the server uses (PC, Macintosh, UNIX, OS/390, or others). It's simply a basic way for information to be passed from the Web server about your request to the application program and back again.

CGI-BIN: The most common name of a directory on a web server in which CGI programs are stored.
The "bin" part of "cgi-bin" is a shorthand version of "binary", because once upon a time, most programs were referred to as "binaries". In real life, most programs found in cgi-bin directories are text files -- scripts that are executed by binaries located elsewhere on the same machine.

CHAP: CHAP (Challenge-Handshake Authentication Protocol) is a more secure procedure for connecting to a system than the Password Authentication Procedure (PAP). Heres how CHAP works:
1) After the link is made, the server sends a challenge message to the connection requestor. The requestor responds with a value obtained by using a one-way hash function.
2) The server checks the response by comparing calculation of the expected hash value.
3) If the values match, the authentication is acknowledged; otherwise the connection is usually terminated.
At any time, the server can request the connected party to send a new challenge message. Because CHAP identifiers are changed frequently and because authentication can be requested by the server at any time, CHAP provides more security than PAP. RFC1334 defines both CHAP and PAP.

CLI: Caller Line Identification this is the number that you are ringing from, if you are making a call to the Internet, many free internet service providers will need you to produce your CLI (show the number you are ringing from). If your number is witheld you will not be able to connect. Try adding 1470 before the number you are dialling to unwithold your CLI.

CLIENT: A client is the requesting program or user in a client/server relationship. For example, the user of a Web browser is effectively making client requests for pages from servers all over the Web. The browser itself is a client in relationship with the computer that is getting and returning the requested HTML file. The computer handling the request and sending back the HTML file is a server.

CLIENT SERVER PROTOCOL: A communication protocol between networked computers in which the services of one computer (the server) are requested by the other (the client).

COLOCATION: Colocation (sometimes spelled "co-location" or "collocation") is the provision of space for a customers telecommunications equipment on the service providers premises. For example, a Web site owner could place the sites own computer server on the premises of the Internet service provider (ISP). Or an ISP could place their network router on the premises of the company offering switching services with other ISPs. The alternative to colocation is to have the equipment and the demarcation point located at the customers premises.

COMPRESSED: Data files available for download from the Internet are typically compacted in order to save server space and reduce transfer times. Typical file extensions for compressed files include zip (DOS/Windows) and tar (UNIX).

CONNECTION: specifically referring to the physical act of one computer making and holding open a means of exchange of data with another computer or server. Connections are often made using MODEMS or similar devices, which make use of the PSTN (Public Switched Telephone Network) to connect machines that are geographically remote from one another. Permanent connections may be created by purchasing Leased Lines from the telephone company. New technologies such as ADSL are now bringing the costs of high-speed, broadband access down. ADSL is described as being an 'always-on' technology, which means that the connection may be left open when 'idle' or, if the connection is terminated, the reconnection is almost instantaneous.
CONTENTION: This refers to the number of people on the same type of account, sharing "modem port" capacity over the BT network, as it relays traffic to and from the Free-Online network. The contention ratio is also an indicator of the amount of time that you may properly expect in return for your subscription. This time is calculated on an 18-hour day and is separately appraised for residential users connecting mainly in the evenings and at the weekends, and business users using the Internet during office hours. Our network capacity is managed based on accumulation of accounts and their contention ratios, with additional bursting capacity and is done so with the aim of providing first time connections.

COOKIE: The most common meaning of "Cookie" on the Internet refers to a piece of information sent by a Web Server to a Web Browser that the Browser software is expected to save and to send back to the Server whenever the browser makes additional requests from the Server.
Depending on the type of Cookie used, and the Browser's settings, the Browser may accept or not accept the Cookie, and may save the Cookie for either a short time or a long time.
Cookies might contain information such as login or registration information, online "shopping cart" information, user preferences, etc.
When a Server receives a request from a Browser that includes a Cookie, the Server is able to use the information stored in the Cookie. For example, the Server might customize what is sent back to the user, or keep a log of particular user's requests.
Cookies are usually set to expire after a predetermined amount of time and are usually saved in memory until the Browser software is closed down, at which time they may be saved to disk if their "expire time" has not been reached.
Cookies do not read your hard drive and send your life story to the FBI, but they can be used to gather more information about a user than would be possible without them.

CSS: A cascading style sheet (CSS) is a Web page style sheet derived from multiple sources with a defined order of precedence where the definitions of any style element conflict. The Cascading Style Sheet, level 1 (CSS1) recommendation from the World Wide Web Consortium (W3C), which is implemented in the latest versions of the Netscape and Microsoft Web browsers, specifies the possible style sheets or statements that may determine how a given element is presented in a Web page.
CSS gives more control over the appearance of a Web page to the page creator than to the browser designer or the viewer. With CSS, the sources of style definition for a given document element are in this order of precedence:
The STYLE attribute on an individual element tag
The STYLE element that defines a specific style sheet containing style declarations or a LINK element that links to a separate document containing the STYLE element. In a Web page, the STYLE element is placed between the TITLE statement and the BODY statement.
An imported style sheet, using the CSS @import notation to automatically import and merge an external style sheet with the current style sheet
Style attributes specified by the viewer to the browser
The default style sheet assumed by the browser
In general, the Web page creator's style sheet takes precedence, but it's recommended that browsers provide ways for the viewer to override the style attributes in some respects. Since it's likely that different browsers will choose to implement CSS1 somewhat differently, the Web page creator must test the page with different browsers.

CU: Abbreviation of see you, commonly used online or on IRC.

CYBERPUNK: Cyberpunk is a sensibility or belief that a few outsiders, armed with their own individuality and technological capability, can fend off the tendencies of traditional institutions to use technology to control society. The term, combining "cyber" and punk, possibly originated in 1980 with Bruce Bethkes short story, "Cyberpunk." An editor of Isaac Asimovs Science Fiction Magazine, Gardner Dozois, is credited with associating the word with a literary movement that includes the science fiction of William Gibson and Neal Stephenson.
The alt.cyberpunk. FAQ lists several categories of groups associated with cyberpunk:
Hackers, who represent the best kind of cyberpunk
Crackers, who attempt to break into computer systems
Phreaks, who attempt to break into telephone systems
Cypher-punks, who attempt to break codes and foil security systems
Additional groups include "transhumans," who attempt to exploit technology to increase life expectancy and human potential and "extropians," a kind of libertarian group that believes in something called "spontaneous order." The writer of the alt.cyberpunk.
FAQ indicates that some people believe cyberpunk to be (intrinsically) indefinable and that anyone claiming to be a "cyberpunk" will likely be laughed off their Usenet newsgroup.

CYBERSPACE: Term originated by author William Gibson in his novel Neuromancer the word Cyberspace is currently used to describe the whole range of information resources available through computer networks, most commonly used to describe the Net