AAC (Advanced Audio Coding)
Definition: A means of compressing digital audio signals that relies on “perceptual coding schemes” (the removal of data related to audio signals that are not perceptible by the human ear), AAC is widely regarded as a more efficient and effective means of audio compression compared to the long-used MP3 format. AAC provides improved audio quality at relatively low bit rates, and supports multichannel audio in that it provides up to 48 full-frequency channels. Because of its improved quality and its use with the increasingly popular iTunes online music service run by Apple, AAC has emerged as a significant challenger to MP3 and other audio compression formats. (See also Compression, MPEG, and MP3.)
AAF (Advanced ...