MPEG-1 are the audio, video coding and compression standards which were developed and approved by the Motion Pictures Experts Group. MPEG-1 Video is used for VCDs. MP3 is the audio encoding and compression standards defined by the MPEG-1 Audio layer. The files using this format have a .MP3 extension. It is widely used for sound files which can be shared online as well as on other media.
MP3 is the preferred audio encoding standard since the data file size is usually much smaller than the standard audio file (less than 1/10th the size) though the sound quality is not affected.This allows a larger number of songs to be stored on the same hard disk space and files to be downloaded or transferred at a faster rate online. This is achieved by using a lossy compression algorithm.