MP3

File Format
Name	MP3
Ontology	Electronic File Formats Audio MP3
Extension(s)	.mp3
MIME Type(s)	audio/mpeg

MP3 is the name commonly given to the audio formats specified by MPEG-1 Layer III and MPEG-2 Layer III, standardized as ISO/IEC 11172-3:1993. It uses lossy compressed data. It is based in part on work by the Fraunhofer Institute, which still holds patents in the format. Other companies may also hold patents encumbering its implementation.

ID3 tags are often used to provide metdata in MP3 files, though they aren't part of the MP3 specification. ID3 V1 defines a fixed-length data block that is always placed at the end of the file. ID3 V2, which has very little in common with V1, defines a block with variable-length frames and allows more flexibility and verbosity.

References

• MP3 (Wikipedia)
• MP3DirectCut -- MP3 editor