The file uses "boxes" or "atoms" to organize data. For example, the ftyp box identifies the file type, while the mdat box contains the actual media.
Researchers often label video files with group codes (e.g., Group 4, Clip 156) for identification in studies involving computer vision, behavior analysis, or forensic video analysis . g4_0156.mp4
If you are looking for technical information regarding the format itself: The file uses "boxes" or "atoms" to organize data