[WindowsCentral.com]

The Guardian of your Playspace is in your Control
One of the most important parts of using Virtual Reality headsets is the play space you have that keeps you safe. The Oculus Rift has created a Guardian system for your play space. The less capable PlayStation VR system will simply give you an "Out of Play Area" message that usually pops up on your headset at the same time your face or body collides with a wall or piece of furniture. Instead of that, Oculus Rift will actually display your boundaries on your in-game view before you hit them.

Full story from the WindowsCentral blog...