How does your cell phone screen distinguish that a video is being played and therefore the screen shouldn’t cut off? Especially since it can do it across various apps?

Question

How does your cell phone screen distinguish that a video is being played and therefore the screen shouldn’t cut off? Especially since it can do it across various apps?

In: Other

Answer 1

The software playing the video is constantly sending updates to the screen to show. Leaving the screen on reddit, for instance, doesn’t do that.