cache - A kind of memory used to make a computer work faster.
CD-ROM - A disk for storing computer information. It looks like an audio CD.
CPU - Central Processing Unit. This is a PC's heart or "brains".
data - usually means the information (text, pictures, audio etc) that you create or share on a computer, as opposed to the programs that manipulate the data.
DOS - Disk Operating System. The original system used for PCs, where you typed in commands instead of pointing and clicking.
driver - A small program that tells a PC how a peripheral works.