Optical disc

This article is about storage media such as CDs and DVDs. For a similarly-named anatomic feature of the eye, see optic disc.

"Optical media" redirects here. For transmission media for light, see Optical medium. For broader definition, see optical storage.

The bottom surface of a 12 cm compact disc (CD-R), showing characteristic iridescence

The optical lens of a compact disc drive

An optical disc is a flat, usually disc-shaped object that stores information in the form of physical variations on its surface that can be read with a beam of light. Optical discs can be reflective, where the light source and detector are on the same side of the disc, or transmissive, where light shines through the disc to be detected on the other side. They may contain analog or digital information, or a mixture of the two. Their main uses are the distribution of electronic media and data, and archival storage.