MP3 is one of the most common file types for song files. Digital music stores and musicians often sell their songs in MP3 format because of the small file size of MP3s. The MPEG-1 Audio Layer III -- dubbed MP3 -- was introduced in the early 1990s and quickly became the preferred format among the consumer audience for its high-quality, small-size audio files.
MP3 technology compresses audio files up to ten times smaller than a CD track, while maintaining the quality. This makes the format ideal for digital downloads and use on portable media players. The compression is similar to that originally used for digital video files. A specific coding scheme removes unnecessary data from the file to reduce size -- sounds the human ear cannot hear or soft sounds that occur at the same time as loud sounds, for example. The result is a song that is approximately 4MB in size as compared to the 40MB audio track found on a CD.
Because of the format's popularity, most digital media players are called "MP3 players" despite the fact that they are capable of playing other formats, including AAC and WAV files. Apple's iPod is one example of an MP3 player; Sony and Creative also make players. Windows Media Player, Winamp and iTunes are software programs that are all compatible with MP3 files; they even let you copy songs from your CDs to your computer as MP3s in a process known as ripping.
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