What is CD mean?

CD stands for compact disc. Compact discs were first introduced in 1982 and quickly became the dominant form of music distribution. Compact discs are a type of optical disc that use laser light to read and write data.

Compact discs are made of polycarbonate plastic and usually measure 12 cm in diameter. They have a diameter of about 8 cm and a thickness of 1.2 mm when empty. The disc is coated with a thin layer of aluminum and then covered with a protective layer of lacquer.

Compact discs are read by a laser beam that …