CD-ROM (Compact Disc, read-only-memory) is an adaptation of the CD that is designed to store computer data in the form of text and graphics, as well as hi-fi stereo sound. Format of the CD-ROM is the same as for audio CDs: a standard CD is 120 mm (4.75 inches) in diameter and 1.2 mm (0.05 inches) thick and is composed of a polycarbonate plastic substrate , one or more thin reflective metal layers, and a lacquer coating. Today, CD-ROMs are standardized and wall work in any standard CD-ROM drive. CD- ROM drives can also read audio compact discs for music, although CD players cannot read CD-ROM discs.
