A very popular movie format, which is officially Part 14 of the MPEG-4 standard. MP4 files are supported by most software media players and many Blu-ray/DVD players as well. They are a common format for movie downloads, and Blu-ray players with front-panel USB ports are generally capable of playing MP4 movies directly from a USB drive. Using the .MP4 extension, MP4 files are containers that hold a mix of multimedia objects (audio, video, images, animations, menus, etc.). See MPEG, M4V and MP4 player.