

Though AIFF and WAV files are smaller in size than .au files, they are still too large to be transported comfortably over the Internet, because of the vast amounts of data they hold. One method of saving storage space and of speeding up Internet download times was the development of the MPEG (Moving Pictures Experts Group) Audio compressed digital sound file.
MPEG is a subcommittee of ISO/IEC (the International Standards Organisation / International Electrotechnical Commission) who define standards for digital audio and video compression, and MPEG Audio is the audio part of the compressed MPEG audio/visual signal, which can be used in conjunction with, or independently of, a visual signal.[6]