CD-ROM

A CD-ROM is a type of CD optical disc storage media that usually allows for about 700 MB of storage space. These were used to replace floppy disks once games and programs became too large. The PlayStation also used CD-ROMs instead of cartridges like Nintendo used, because Sony favoured the increased storage space of CD-ROMs, despite the longer access times for disc-based content.

History
The CD-ROM format was developed by Japanese company Denon in 1982. It was an extension of Compact Disc Digital Audio (CD-DA), and adapted the format to hold any form of digital data, with a storage capacity of 553 MB. CD-ROM was then introduced by Denon and Sony at a Japanese computer show in 1984.