Each time you start it up, you make a safe perimeter with it. While you're playing any game, it has you stay in that
space. At least, it does with the MetaQuest 3; I haven't used the MetaQuest 2.
Some of the games my son plays have "augmented reality," where you see your own surroundings (couches, t.v., stairs, etc.) but also work with virtual elements in those surroundings (like solving puzzles, defusing bombs, etc.).