The MP4 file format defines extensions over the ISO Base Media File Format. These support MPEG-4 codecs and features like scenes. Some extensions are used by other ISO base media formats too. A list of registered extensions is published.
The .MP4 extension shows a container format file. It is based on the QuickTime file format. Video is compressed by MPEG-4 standard. Audio is AAC. This stores movie, subtitles and images.
MPEG developed and maintains MP4. It extends the QuickTime File Format used by .MOV and .QT. Like those, MP4 can contain video, audio, subtitles, and other data. Each stream may use different codecs.
You can play MP4 on Windows, Mac, Linux, and phones. VLC media player, MPlayer and iTunes are popular. Streaming over internet is possible too.
MP4 files use the MPEG-4 encoding standard. The .mp4 extension comes from the MP4 format’s official name. MP4s are widely supported by players. They are compressed, making small sizes for sharing. They work on many devices too. Streaming quality stays high. Embedding in web pages is possible.