AAC belongs to the class of perceptually-oriented traditional waveform codecs, meaning that it aims at reproducing the waveform of the original input audio signal with a minimum amount of data while taking into account psychoacoustic principles to minimize the audibility of coding effects. Other well-known representatives of this class of codecs are MPEG-1/2 Layer 2, MPEG-1/2 Layer 3 (better known as mp3) and Dolby AC-3 (better known as Dolby Digital). Today, AAC constitutes the most efficient waveform compression standard.