CD

CD is the acronym for Compact Disc.

Compact Disc

A digital optical disc for storing audio, video, or data. Some key points about CDs:

Developed jointly by Philips and Sony in the 1980s, CDs became commercially available in 1982.
CDs are made of polycarbonate plastic, with a diameter of 120mm (4.7 inches) and a thickness of 1.2mm.
Data is encoded on the disc as a series of microscopic pits and lands read by a laser in the CD player.
The standard CD format can hold up to 74-80 minutes of uncompressed audio or 650-700MB of data.
Audio CDs are used for music distribution, while data CDs can store various types of digital information, including software, video, and documents.
CDs offer advantages such as durability, portability, and good audio quality. However, they have largely been replaced by newer technologies like digital downloads, streaming, and USB drives for data storage.