A Cache is a temporary storage area for frequently used or recent data. An example of your computer using its Cache is on a website. The first time you visit a site, the computer will store it in its Cache, so when the thext time you go to this website, the Browser will display the site from the Cache. This saves time as it means you dont need to download the page content again to view it.

Stands for Compact Disc - Read Only Memory. Most software is supplied on CD-ROMS. The data stored can be read, but not changed.

Stands for Compact Disc - Recordable. A CD-R will allow you to record something on to it only once. Once a CD-R has been recorded on to, it becomes a CD-ROM.

Stands for Compact Disc - Re-Writable. A CD that can be recorded on to time and time again. As it is re-usable, these usually cost a little more than CD-Rs.

Stands for Common Gateway Interface. This is a way in which a Server can run Programs or scripts and output to a user's web Browser.

A value calculated from pieces of data that can be used to verify the data has not been altered.

A client is a computer or a Program that is connected to a file Server. The client is able to download and run software held on the server.

CMYK is a term associated with printers. CMKY stands for Cyan, Magenta, Yellow, Keystone Black - which are the four standard colours used by most printers. The printer sprays different amounts of these colours on to the page being printed in the right volume to make nearly any colour imaginable.

A virus that exploits the fact that when an operating system has 2 files of the same name in a directory, it uses the file extension to decide which to run, for example, computers running DOS will choose filename.com over filename.exe . A companion virus would write itself in to a .com file, and give itself the name of an existing .exe .

A way in which anti-spam software works. Complex Dictionary Checking not only finds words often used in spam, it can also distinguish words made up of numbers and special characters, $uch as th1s.

A Cookie is a small data file stored on your computer by certain websites. Cookies store your preferences for that particular site, which makes thing a lot faster when revisiting, for example for sites that require you to log in, a cookie will remember your username for next time.

Central Processing Unit, also known as the processor. Essentially your computers brain. CPU manufacturers include AMD and Intel.

Stands for Customer Relationship Management. This software allows you to organise all the details you may have about clients and business contacts, and share the information with your colleagues.

A type of Monitor. CRT stands for Cathode-Ray Tube, and looks like the traditional monitor assosiated with computers. Inside the monitor there is a heated vacuum tube that contains electrons that are directed into a beam, which produces light. With modern advances with LCD and Plasma Screens, CRT monitors are likely to be phased out.

Stands for Comma Separated Values. This is type of file format in which entries in the file (such as in a spreadsheet) are seperated by commas. This file format does no support macros however, so that it can not spread macro viruses.