You can record a video of your screen while you're using it.
To start recording, open quick settings and tap 
If needed, adjust sound and screen touch options.






Tap Start to start the countdown timer.
While recording, you'll see 
To view a recording immediately after you capture it, swipe down from the top of the screen and tap the 
To view any time, open Photos, Files, or another media viewing app, and look for the Screen record folder.