The 1.44-megabyte floppy-disk drive is an endangered species largely because its primary predator, the CD-rewritable drive, uses media that can store up to 700MB per disk and costs only about $100. CD ...
it allows you to play audio cd's. it's not really necessary anymore; wmp 7.1 and up, as well as other apps transfer music data digitally through the ide bus, bypassing the analog cd cable.