Source : Free On-Line Dictionary of Computing

MPEG-4 AAC Main Profile
     
         A successor of
        {MP3} allowing transparent coding at data rates of 70-75% of
        that of {MP3}.  It is very different from MP3, only used
        {MDCT}, no {subband coding}.  It is much more complex that
        {MP3} and {MPEG-2 AAC Low Profile}.
     
        (2001-12-08)