The 'Degree of Freedom' (DOF) concept stems from virtual reality and describes the degrees of freedom in the influencing a virtual object that an inputting device gives the user. The spatial position and all the movements of an object are clearly defined by six parameters (x/y/z coordinates, translation along the x/y/z axis and the rotation angle around the x/y/z axis).
Theoretically, an inputting device with six degrees of freedom is necessary for interaction in a spatial environment.
The most common inputting device - the mouse - only has two degrees of freedom (x/y translation). Despite this limitation the mouse makes it possible to make natural body movements such as pointing and grasping inputting actions. Its use is therefore not by any means limited to a two-dimensional influence on objects.

The object being depicted can be manipulated easily and simply through its seemingly three-dimensional surroundings via the correspondent interpretation of mouse movement. This is the case despite the fact an input device with six degrees of freedom would theoretically be necessary.