Track (optical disc) Track (optical disc) On an optical disc, a track (CD) or title (DVD) is a subdivision of its content. Specifically, it is a consecutive set of "sectors" (called "timecode frames" on audio tracks) on the disc containing a block of data. One "session" may contain one or more tracks of the same or different types. There are several kinds of tracks, and there is also a sub-track index for finding points within a track. Blu-ray discs can also be written in a sequential, session based mode modelled on CD and DVD. A Blu-ray "track" refer to the entire physical storage
History of optical storage media History of optical storage media Although research into optical data storage has been ongoing for many decades, the first popular system was the Compact Disc, introduced in 1982, adapted from audio (CD-DA) to data storage (the CD-ROM format) with the 1985 "Yellow Book", and re-adapted as the first mass market optical storage medium with CD-R and CD-RW in 1988. Compact Disc is still the "de facto" standard for audio recordings, although its place for other multimedia recordings and optical data storage has largely been superseded by DVD. DVD (initially an initialism abbreviation of "Digital Video Disc," then modified to "Digital