The Audio Compact Disc, a digital optical disc format, was commercially released in October 1982 in Japan and in March 1983 in North America and Europe. Since then, the Audio CD has become the most popular audio format worldwide. Unlike older formats, the Audio CD carries digital audio signals, with up to 80 minutes or 700 MB of audio. The maximum audio quality for a CD is 16-bit PCM stereo, encoded at a 44.1 KHz sampling rate.
If a soundtrack album for a film for television series is longer than 80 minutes, it is usually split into two or more parts and released in multiple discs.