172_720p.mp4 -

: This is likely a unique ID or index number within a database. In video streaming, it can refer to a specific "profile" or iTag (internal format code) used to identify a stream's settings.

: If you found this in your browser cache or temporary files, it’s a segment of a video you recently watched. 172_720p.mp4

: This indicates the resolution . Lenovo defines 720p as High Definition (HD) with a frame size of 1280x720 pixels. The "p" stands for progressive scan, which means the image is drawn line-by-line for smoother motion. : This is likely a unique ID or