CD-ROM. Conceptual image of hands holding a CD-ROM (compact disc-read only memory) reflecting images of printed circuitry. This may represent the use of compact discs (CDs) to store information for retrieval using a computer. The disc is made of plastic pressed with a series of fine depressions. These pits encode digital information and are read by a laser. The encoded layer is coated with a film of metal to reflect the laser light.