A MP3 player is an electronic device that can play digital audio files. The term 'MP3 player' is a misnomer, as most players play more than the MP3 file format. A more accurate, but less utilized term is DAP (Digital Audio Player).
Since the MP3 format is widely used, almost all players can play that format. In addition, there are many other digital audio formats. Some formats are proprietary, such as MP3, Windows Media Audio (WMA), and Advanced Audio Codec(AAC). Some of these formats also may incorporate digital rights management (DRM), such as WMA DRM, which are often part of paid download sites. Other formats are patent-free or otherwise open, such as Vorbis, FLAC, and Speex (all part of the Ogg open multimedia project).