Six Degrees of Freedom (6DoF) Tracking
Formal
Refers to the specific number of axes that a rigid body is able to freely move in three-dimensional space.
Practical
In AR and VR, 6DoF describes the range of motion that a head-mounted display allows the user to move on an axis in relation to virtual content in a scene. Three of the degrees refer to the motion of the user's head—left and right (yaw), backwards and forwards (pitch), and circular (roll)—while the remaining three pertain to the movement within the space—left and right, backwards and forwards, and up and down.
