MP4 (MPEG-4 Part 14) is a digital video file format that is widely used for storing and sharing video content. It is a container format, which means that it can store multiple audio, video, and subtitle streams in a single file. MP4 files use a variety of video and audio codecs, including the H.264 video codec and the AAC audio codec, which provide high-quality video playback with relatively small file sizes. The format is widely supported across a range of devices and media players, making it a popular choice for distributing video content online. MP4 files can be played back on a variety of media players, including VLC, Windows Media Player, and QuickTime, and can also be converted to other more widely supported video formats like AVI or MOV using compatible media conversion software. Overall, MP4 is a useful video file format for storing and sharing high-quality video content, particularly for distributing video content online due to its widespread support and relatively small file sizes.