Use .WAV files for TV, radio, DVD or any other media requiring top uncompromised audio quality. WAV files are lossless, uncompressed, broadcast CD quality music files. WAV files are also the right choice for loops to be processed with Flash for web animations.
Use MP3 files for web pages, web videos, in fact for anything on the Internet. An MP3 file is a compressed music file. It loads rapidly and still plays with a very good sound quality.