optical disk

A digital data storage technology that uses optical media to store information. Optical disks are slower, but store more data and cost less per unit of stored data than magnetic disks. Several optical platters can be installed in a single device called a jukebox. Optical disks are used when very large amounts of data need to be stored.

A storage medium from which data is read and to which it is written by lasers See also compact disk (CD), digital versatile disc (DVD), magnetic media, and storage media.

A flat, circular, plastic disk coated with material on which bits may be stored in the form of highly reflective areas and significantly less reflective areas, from which the stored data may be read when illuminated with a narrow-beam source, such as a laser diode. Note: The bits are stored sequentially on a continuous spiral track.