optical disc



  • A digital optical storage medium, usually 12 centimeters in diameter, whose contained information is encoded in microscopic pits on its metallic surface, which is protected by a plastic layer. To recover the recorded content, a laser is focused on the metallic surface of the disc, and the reflected light is modulated by the code on said disc. Since there is no contact between the pickup and the recorded surface, wear is minimized, while the protective layer helps avoid reading errors due to dust or minor marks on the surface of the disc. Any form of data may be recorded onto a disc, and formats include DVDs, DVD+RWs, CDs, and CD-ROMs. Also spelled optical disk. Also called disc (1).
  • synonymoptical disk