hii! im new to speedrunning and i saw the categories and got really confused. what do they all mean?

NMS Stands for "No Major Skips" which means you basically can't do big skips that skip too much of the gameplay.

OOB stands for "Out Of Bounds" Which means you can leave the confined area of regular gameplay to skip sections of the game. (de-loading areas to get outside walls etc.)

Unrestricted pretty much means anything goes in order to beat the game fast from what I understand.

Hope this helps :)