The CD-ROM drive first appeared in the home PC around 1993. Also called an Optical Drive, it was only for read only data, hence the name - Compact Disc Read Only Memory. A single CD could hold up to 650Mb of data, which meant larger programs that took up several floppy disks, could now fit on one CD.

Capacity wasn't the only plus point, CD-ROM drives could read and transfer data alot faster than the floppy drive. As time went on, CD drives became faster, and it wasn't long before the first CD-R's came onto the market - CD-R standing for Compact Disc Recorder. Now you can compile and 'Burn' your own CD's.

To bring us up to date, the modern PC is now fitted with what's called a Combo (Combination) drive. This drive can read, write & re-write Compact Discs & Digital Versatile Discs (DVD's). There are two types of DVD, the first being the standard 4.7Gb disc, and the second being 9.4Gb (Dual Layer). For an example of size, you can get about 7 CD's of data onto a 4.7Gb DVD.