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

C

Cable modem
A device allowing high speed access to the Internet over the same wiring used by Cable Television networks.

Cabling
Cables used to link computers together so they form a network and can communicate with each other.

Cache
A folder on a computer that stores pages already visited on the web. Used to reduce download times, especially when clicking the ‘back’ button on a web browser.

CD-ROM
One of the most popular formats for storing large amounts of electronic information. A CD-ROM can store 400 times as much information as a floppy, equivalent to 300,000 pages of text or one hour of video and audio footage.

Certificate Authority
An issuer of Security Certificates used in SSL connections.

CGI - (Common Gateway Interface)
This is the mechanism by which a ‘script’ receives the data entered by a web user (when you fill in an online form and click ‘submit’, for example).

CGI-BIN
The most common name of a directory on a web server in which CGI programs are stored.

Client/server
A type of computer system that has a powerful main computer (the server or file server) and a string of computers linked to it (clients).

Co-location
This is where a company places its own server (high-powered computer) in the data centre of a hosting company. Responsibility for the maintenance of the server resides with the company that owns it.

Cookie
Small piece of data sent by a website to enable personalisation and quicker access the next time you visit. On your return, the cookie is read, as the basis for displaying the web pages, and retrieves details like username, account number, previous transactions, etc. stored in the cookie.

Configuration
The way a computer or piece of software is connected or set up to operate in a particular way.

Contention rate
This describes the maximum number of users sharing the bandwidth on the connection between your local exchange and the ISP. A contention ratio of 20:1 means never having to share bandwidth with more than 19 other users.

Coverage
The land area where mobile phone services are available.

CSS (Cascading Style Sheet)
A standard for specifying the appearance of text and other elements. CSS was developed for use with HTML in Web pages but is also used in other situations, notably in applications built using XPFE. CSS is typically used to provide a single “library” of styles that are used over and over throughout a large number of related documents, as in a web site. A CSS file might specify that all numbered lists are to appear in italics. By changing that single specification the look of a large number of documents can be easily changed.