MPEG-1 Audio Layer 3 or MPEG-2 Audio Layer 3 or MPEG-1 or 2 Audio Layer III, more commonly referred to as MP3 it is the file extension which is used for Audio signals. MP3 is an audio-specific format that was designed by the Moving Picture Experts Group as part of its MPEG-1 standard and later extended in MPEG-2 standard. The group was formed by several teams of engineers at Fraunhofer IIS, AT&T-Bell Labs. MPEG-1 Audio Layer 2
WAV files are digitized music files that can be stored on computers, downloaded, or e-mailed. MP3 files are similar to WAV files but are compressed to 1/10th the size yet maintain high sound quality. Bit rates are specified in the MPEG-1 Audio Layer III standard: 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256 and 320 kbit/s
Many other lossy and lossless audio codecs exist. Among these, mp3PRO, AAC, and MP2 are all members of the same technological family as MP3 and depend on roughly similar psychoacoustic models. The Fraunhofer Gesellschaft owns many of the basic patents underlying these codecs as well, with others held by Dolby Labs, Sony, Thomson Consumer Electronics, and AT&T