Kinda confused on how adjusting graphical settings works in general with VR. I use an older HTC Vive (the original from what 2017 was it? whatever it was) and naturally uses steam VR. In steam VR itself it allows me to adjust the resolution per eye and I currently have it set at 200% and it says "2128x2364"

I don't get it. 4K resolution is 3840x2160. Am I running my headset at somewhere between 2k to 4k with that setting? how is that even a thing the headset is old as shit and can't support such resoultuion, hell I could make those numbers way higher with 300, 400, 500% as well. How the hell does this even work?