Since "7711" is a numerical ID and "720p" refers to the resolution (1280x720 pixels), the file is likely from one of these sources:
"High Definition" (Standard HD). It’s great for social media (Instagram/TikTok) and web use, but may look blurry on large 4K monitors or TV screens. 7711_720p.mp4
The "Swiss Army Knife" of video. It can play almost any .mp4 even if the file is slightly corrupted. Since "7711" is a numerical ID and "720p"
If you are having trouble playing the video, use these highly compatible players: 7711_720p.mp4
Knowing the technical limits helps you decide how to use it: Usually 16:9.
It may be a proxy file or a placeholder used by an editor to save processing power. 2. How to Open the File