Compact disc is a system of recording or storing of digital audio or video information using laser technology on a metal disc. The data is stored on a small aluminium disc in the form of microscopic pits etched by a laser beam. The stored information is read by using a laser beam which scans the rotating disc much like the replaying of phonograph records. The pits read as 0 and the smooth surface as 1, creating the sound digitally. As the laser beam does not wear out the surface, music replayed from an audio compact disc is without any distortion or noise and such music compact discs have virtually replaced phonograph records or turntables. The compact disc also allows recording and storage of text, pictures as well as sound simultaneously on a single disc and it has enormous capacity to store data. For example, the entire text and pictures contained in the 30-volume Encyclopedia Britannica can be stored on a single compact disc. Because of their versatility, adaptability and large storage capacity, compact discs are likely to be the choice medium for home entertainment and computer systems of the future.