MP3 (MPEG-1 Audio Layer-3) is a standard technology and format for compressing a sound sequence into a very small file (about one-twelfth the size of the original file) while preserving the original level of sound quality when it is played.

MP3 files (identified with the file name suffix of ".mp3") are available for downloading from a number of Web sites. Many Windows users will find that they have a player built into their operating system. Otherwise, you can download a player from one of several popular MP3 sites.

MP3 files are usually download-and-play files rather than streaming sound files that you link-and-listen-to with RealPlayer and similar products (However, streaming MP3 is possible.) Winamp (PC), iTunes(Mac), and mpeg123 (UNIX) are popular MP3 players, but there are many others. To create an MP3 file, you use a program called a ripper to get a selection from a CD onto your hard disk and another program called an encoder to convert the selection to an MP3 file.

Most people, however, simply download MP3s from someone else and play them.