The first CDs were audio CDs, which eventually replaced audio tapes (which earlier replaced records). Audio CDs have the advantage of allowing the user to jump to different places on the disc. CDs can also be listened to an unlimited number of times without losing quality. Audio tapes can start to lose quality after listening to them as few as ten times. This is because the laser that reads the data on a CD doesn't put pressure on the disc, whereas the playheads on a tape deck slowly wear away the magnetic strip on the tape.
In 1985, CD-ROMs hit the computer market. Because they could store far more information than floppy discs (700 MB compared to 1.4 MB), CDs soon became the most common software format. In 1988, the CD-R (CD-Recordable) technology was introduced, allowing computer users to burn their own CDs. However, this technology did not become mainstream until the late 1990s. A smaller 3" CD, called "CD-3" is also available and is readable by most tray-loading CD-ROM drives. For a timeline of the history of the CD, visit OneOff Media, Inc.