MP4 stands for MPEG-4 Part 14 and is one of the most common video formats. The MPEG-4 standard appeared in 2001, but the version reissued in 2003 is now in use. The MP4 format is an add-on plug-in to MPEG4, which is a standard for storing encoded multimedia content. The MP4 container has been specially designed for streaming video online. MP4 files can contain video, audio, graphics, and subtitles.