What is a mp3 player ?

A digital audio player (DAP) is a device that stores, organizes and plays digital music files. It is more commonly referred to as an MP3 player (because of that format's ubiquity), but DAPs often play many additional file formats. Some formats are proprietary, such as Windows Media Audio (WMA), and, to a degree, Advanced Audio Coding (AAC) and MP3. Some of these formats also may incorporate restrictive digital rights management (DRM) technology, such as WMA DRM and Apple's "FairPlay", which are often part of certain paid download sites. Other formats are completely patent-free or otherwise open, such as Ogg Vorbis, FLAC, Speex (all part of the Ogg open multimedia project), and Module file formats.

There are three main types of digital audio players:

* MP3 CD Players - Devices that play CDs. Often, they can be used to play both audio CDs and homemade data CDs containing MP3 or other digital audio files.
* Flash-based Players - These are solid state devices that hold digital audio files on internal or external media, such as memory cards. Due to technological limitations, these are relatively low-storage devices, commercially ranging from 128MB to 8GB, such as the 2nd generation Ipod Nano, which can often be extended with additional memory. As they are solid state and do not have moving parts, they are very resilient. In effect, they do not suffer limitations that owners of Hard Drive-based players face, such as fears of dropping their player or fragmentation. Such players are generally integrated into USB keydrives.
* Hard Drive-based Players or Digital Jukeboxes - Devices that read digital audio files from a hard drive. These players have higher capacities, ranging from 1.5GB to 100GB, depending on the hard drive technology. At typical encoding rates, this means that thousands of songs — perhaps an entire music collection — can be stored in one MP3 player. Due to their capacity and physical size, image and video media support is becoming standard among Hard Drive-based players. The Apple iPod and Creative Zen are examples of popular digital jukeboxes.