: Denotes the video resolution , specifically 1280x720 pixels, which is standard High Definition (HD) for streaming and digital downloads.
Most files with this naming convention refer to the popular anime series (Gate: Thus the JSDF Fought There!). About Us - Gate Anime News gateanime-com-gk4-05-720hd-mp4
The string appears to be a specific filename or metadata tag associated with a digital video file, likely hosted or distributed by a platform like Gate Anime News . : Denotes the video resolution , specifically 1280x720