Compact disc
Compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony and released in 1982. The format was originally developed to store and play only sound recordings (CD-DA) but was later adapted for storage of data (CD-ROM). Several other formats were further derived from these, including write-once audio and data storage (CD-R), rewritable media (CD-RW), Video Compact Disc (VCD), Super Video Compact Disc (SVCD), Photo CD, PictureCD, CD-i, and Enhanced Music CD. The first commercially available audio CD player, the Sony CDP-101, was released October 1982 in Japan.
Capacitance Electronic Disc
RCA began videodisc research in 1964, in an attempt to produce a phonograph-like method of reproducing video. Research and development was slow in the early years, as the development team originally comprised only four men, but by 1972, the CED team at RCA had produced a disc capable of holding ten minutes of color video (a portion of the "Get Smart" episode "A Tale of Two Tails", re-titled "Lum Fong").