: An MP4 file can simultaneously hold video and audio streams, still images, and metadata like subtitles or chapter information.
The MP4 format, first introduced in 2001 and refined in 2003, is based on Apple’s QuickTime File Format. It is not a method of video encoding itself but rather a "digital container" that wraps around various data tracks. RTS0805 mp4
The internal structure of an MP4 file is organized into a hierarchy of "boxes" or "atoms". MP4 files explained: How to open and use - Adobe : An MP4 file can simultaneously hold video
: By separately compressing audio and video segments—often using Advanced Audio Coding (AAC) for sound and H.264 or HEVC for video—the format achieves high-quality playback with significantly reduced file sizes. The internal structure of an MP4 file is
: It is arguably the most portable video format, natively supported by smartphones, web browsers (via HTML5), and diverse media players like VLC Media Player . Technical Architecture