Players
A digital audio player (also known as a DAP, or as an MP3 player, due to that format's ubiquity) is a device that stores, organizes and plays digital audio files. more...
It comprises three main types: MP3 CD players, simply CD players capable of reading the MP3 file format; flash-based players, holding files on solid-state media internal or external to the device; and hard drive based players (or 'digital jukeboxes'), holding files on an internal hard drive.
History
The precursors to DAPs were portable CD players and MiniDisc players (neither being generally considered a "digital audio player"). Non-mechanical DAPs were introduced following the popularity of the precursors.
The first non-mechanical digital audio player in the world was created by SaeHan Information Systems in 1997. The MPMan F10 was later OEMed to the American market through Eiger Labs. The first non-mechanical digital audio player on the American market was the Eiger Labs MPMan F10, a 32MB portable that appeared in the summer of 1998. It was a very basic unit and wasn't user expandable, though owners could upgrade the memory to 64MB by sending the player back to Eiger Labs with a cheque for $69 + $7.95 shipping.
The second DAP (but widely considered the first mass market player) was the Rio PMP300 from Diamond Multimedia, introduced in September 1998. The Rio was a big success during the Christmas 1998 season as sales significantly exceeded expectations, spurring interest and investment in digital music. The Recording Industry Association of America soon filed a lawsuit alleging that the device abetted illegal copying of music, but Diamond won a legal victory on the shoulders of Sony Corp. v. Universal City Studios and digital audio players were ruled legal devices.
Read more at Wikipedia.org