MP3 is an audio file extension that stands for Moving Picture Experts Group (.mpeg) Audio Layer 3. MPEG is a file extension like .doc or .pdf.
According to Whatis.com, MP3 is a standard technology and file format for compressing a sound sequence into a small file that is one-twelfth of the original size. MP3 files preserve the quality of the original sound while compressing the size of the digital audio file. MP3 files are designed for downloading and then listening to the sounds. According to Whatis.com, MP3 is a powerful algorithm in audio encoding developed by the Moving Picture Experts Group.