Other CD formats include CD-ROM [Compact Disc–Read Only Memory], a form of CD that is read (but not written to) by computer using a CD-ROM drive and that can contain computer programs and digitized text, sound, photographs, and video; CD-R [Compact Disc–Recordable] and CD-RW [Compact Disc–ReWritable], which can be written to one time and multiple times, respectively. Interactive CDs (CD-I, CDTV, and other formats) can store video, audio, and data. Photo CD is a format that holds digitized photographs and sound. There are also CD-ROMs that require special players with built-in microcomputers.
Other optical disk formats include digital versatile (or video) discs and videodiscs. A digital versatile disk (DVD) holds far more information than a CD. DVD players are backward compatible to existing technologies, so they can also play a CD (or CD-ROM), but a CD player cannot be used with a DVD (or DVD-ROM). The videodisc, or laser disk system, uses 12-in. (30-cm) disks for video recording. Its technology, unlike that of the CD, is an analog system that uses a laser to read a variable-width track, much like a conventional phonograph record.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
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