MP4 specifically refers to the MPEG-4 part 14. A standard audio and video container that is part of the MPEG-4 specification developed by ISO / IEC.
A MP4 is similar to the popular AVI, but has several advantages:
- Native support for embedded subtitles (AVI can also have, but only through hacks like the one used in DivX6).
- Better support for video coding standard H.264, also known as MPEG4 AVC.
- Being encoded, an MP4 file may have been created with several different types of codecs, including DivX and XviD But as DivX and XviD are relatively well served by the encoded AVI file (which is much more popular), you're more likely to find a MP4 which consists of streams created by codecs uncommon.