Winamp is an audio player. It plays music, or any other recorded sound, on your computer. Winamp also has a number of popular plug-ins for visualization (cool effects that synchronize with the music), input, output, and other purposes. It also allows the look of its interface to be customized through the use of skins. Though Winamp is most popular as a player for MP3s (MPEG audio layer 3 files), it also supports a number of other formats.