The , officially known as Compact Disc Digital Audio (CD-DA) , is a digital optical disc data storage format. Co-developed by Sony and Philips and commercially introduced in 1982 , it revolutionized the music industry by offering superior sound quality, durability, and portability compared to analog formats like vinyl and cassettes. Technical Design & Functionality audio compact disc
: A 1.2 mm thick layer of clear polycarbonate plastic . The , officially known as Compact Disc Digital
: Microscopic depressions called pits and flat areas called lands are pressed into the plastic. audio compact disc