Anchoring of Information
Anchored to head: In this case, the information moves along with the head movement of the user and always stay in front of him/her.
The virtual objects follow the head movement and stay in the view all the time.
Anchored to space: The virtual elements are anchored to real-world coordinates in 3D space around the user. Hence the information stays at a particular position and the user sees it only when he/she is looking in its direction.
The virtual object stays at a particular position and doesn’t move with the head movement.