An MP4 file is a video file that is compressed with MPEG-4 compression. Most MP4 files typically contain both audio and video tracks.

The MP4 format was developed by the developed by the Moving Picture Experts Group (MPEG). It is a standard video format that can be played by most video playback programs. Many video podcasts are saved in the MP4 format. These videos can be played directly within iTunes or may be transferred to an iPod or iPhone.