It's supposed to be QHD+, so make sure it's not something worse ...
If you never alter the settings in a Samsung's camera app before you snap a picture or record a video, you're not using the ...
On a PC, apps like games and maybe anything else that is using the GPU directly to process the display generally work at fixed resolutions, like 1920x1080 or 216x1440, and when running in full screen ...