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
CGI - Common Gateway Interface
CGI is a standard for interfacing external applications with Web servers. An example is a CGI program that allows you to hook up a database with the WWW, to allow other people's browsers to access it. CGI allows the Web to input data into the database, and then display the information once it is retrieved.

CD-ROM
A CD-ROM (Compact Disk - Read Only Memory) is for permanent data storage. This disk can only be read on the computer, data can’t be saved to it. A CD-ROM can store up to 700 megabytes (MB) of data.

CD-R
A CD-R (Compact Disk - Recordable) is for permanent data storage. This disk can be used to save data to. It can have data added at various times (multisession recording), but it can only hold up to 700 megabytes. Previous data can’t be overwritten.

CD-RW
A CD-RW (Compact Disk - Rewritable) is for permanent data storage. Data can be added to it in multiple sessions and data can be overwritten, just like a floppy or hard disk.

Chat
Chats are a way for people to communicate in real time over the Internet. They are text based and nowadays are often applets written in Java and embedded in a Web page. One of the original chat applications was IRC, or Internet Relay Chat.

Cookie
A cookie is a message delivered to your Web browser which is stored on your computer and can be read each time the browser requests a page from the server. The main purpose of a cookie is to identify users. This information can be used in a number of ways, one of which is to customise Web pages for return visits to websites.

Compiler
A compiler is a program that takes statements written in a particular programming language and turns them into machine language, or ìcodeî. The programmer writes in a language such as Pascal or C, one line at a time using an editor. The file that is created contains what are known as source statements. When running, the compiler first analyses all of the language statements and then builds the output code, making sure that there are no errors. The output is called object code, which the processor can then execute.