CPU - Central Processing Unit. This is a PC's heart or 'brains'.

DOS - Disk Operating System. The original system used for PCs. You type in commands instead of pointing and clicking.

Driver - A small program that tells a PC how a peripheral works.

Electronic mail (email, e-mail) - Messages sent from one computer to another. You can see email on the screen or print it out.

Floppy disk - A cheap, removable disk used for storing or transferring information. It is floppy (soft) because it is plastic.

Folder (directory) - A sub-division of a computer's hard disk into which you put files.

Font - A particular sort of lettering (on the screen or on paper).

Format - All hard disks and floppy disks have to be electronically prepared for use by a process called formatting.