compact disc

n. (CD, CD-ROM, CD-I, VCD, CD-V, abbr.) A 120mm (4.7 inch) digital optical disk, commonly used for sound recordings and computer data, that stores approximately 600 MB of data in a spiral track.


The original CD format was introduced in 1983 by Sony and Philips as a medium for recorded sound. Variations of the format are now used to store other types of data. Other formats include CD-ROM (CD Read Only Memory) for computer data, CD-I (CD Interactive) that allowed interactive multimedia to be played on a television, VCD (Video CD) for video recorded in MPEG-1, CD-V (CD Video) for uncompressed video, and Photo CD. The original CD format was read-only. Later versions allowed write-once and read-write capabilities. Writable versions include CD-R, CD+R, and CD-RW. Although the spelling 'disk' is common in the United States, the format is spelled 'disc.'