Stands for "MPEG-1 Audio Layer-3." MP3 is a popular compressed audio file format that helped popularize digital music downloads beginning in the late 1990s. MP3 files are typically about one tenth the size of uncompressed WAVE or AIFF files, but maintain nearly the same CD-quality sound. Because of their small size and good fidelity, MP3 files have become a popular way to store music files on both computers and portable devices like the iPod.
To listen to MP3s on your computer, you'll need an MP3 player like Nullsoft Winamp (for Windows) or Apple iTunes (for Mac and Windows). Most MP3 players also allow you to create MP3 files from CD audio tracks or other from other audio file types. Once you have converted your favorite songs to MP3 files, you can transfer them to a portable music player, like the Apple iPod, Microsoft Zune, or a music-enabled cell phone. You can also burn the MP3 files to a CD, which can be played in MP3-compatible CD players.
File extension: .MP3