What can Xbox Game Bar capture or record from the screen? Initially I thought it could only capture games because of its name. But the instructions say “Go to the game or app you want to record.” I tried recording a video being played with VLC but could not get it to work. Of course I may be doing something wrong.

I don't want to create & record content. I would like to capture/record some existing webinars & tutorials.

Is Xbox Game Bar only for games? How does it know what’s on the screen?