It can be used to reduce file size of some MP3 song so it could be easier sent as E-mail attachment, or to encode some captured audio from different audio sources : TV card, line-in or microphone saved in smaller, more convenient MP3 format . You can use Free MP3 Converter together with Winamp software to write some of your existing MP3-s into wave format (by using Winamp Disk Writer plug in). After you create .wav file you can edit it with wave editing software (Sound Forge ,Cool Edit) and/or use Free MP3 Converter to encode .wav file into MP3 according to audio quality preferences or mp3 file size need . Free MP3 Converter is fully featured MP3 encoder .Very easy to use, with bunch of options. Supports encoding of .raw and .wav files, variable bit rate encoding, adjustable bit rates (30-320 KHz), CPU priority adjust, IO frequency adjust, sampling rates, different encoding modes (Mono, Stereo, Joint Stereo) and many other options.