A file used by Video Relay Services contains one or more tracks, each has a particular type of data: audio, video, effects or text (for subtitles, for example). Each track contains a track media, either digitally encoded stream (with a codec such as Cinepak, Sorenson, MP3, JPEG, DivX …) or a reference to a media in another file or network.
Internally, the file format features the atoms tree. Each uses a four-byte identifier to determine structure. An atom can be a parent to other atoms or it can contain data (but it can not be both at once). These files usually have the extension, mov.
In 1997 QuickTime is used by thirteen million people streaming playback, making it one of the major software for this purpose, with HTML5, VLC, Flash, iTunes, Windows Media Player and RealPlayer. In 2013, its market share is greatly reduced due to the quasi-monopoly of Flash technology.
