It is legal to own a MP3 file, only if you have the CD, or the author s permission. MP3 Players are programs written to play MP3 files. There are plenty different kinds of MP3 players, for almost every type of platform. Skins are files that you can download and install to change the appearance of your MP3 player. Encoders are a programs that allow your to change your .wav file to a MP3.
Decoders do the opposite.
They allow you to change a .mp3 file to a .wav file. Recently Diamond Multimedia released a Rio Player. A device that can copy songs from your hard drive to the player, and then play the songs back like a CD player, except it doesn't skip. Look for other devices to follow. A technique used to capture continuous phenomena, whereby periodic snapshots are taken.