All devices that register movement and user inputs are considered to be sensors. They belong to the material part of the user interface of the computer along with the effectors. Sensors are divided into trackers and input devices.
The position and motion of the user create an interaction between the person and machine on the basis of body movement that is not experienced as a conscious inputting activity. Even today's inputting standard, the mouse, combined with graphical user interfaces make it possible for the user to complete part of the inputting process through metaphorical natural pointing and grasping. Inputting devices are transitional objects and therefore part of the staging space.

The objects on the screen react to the position of the cursor. This example is intended to stress that mouse movement represents an inputting action that is no lopnger experienced consciously.
The circle can be moved by clicking and dragging . It can be scaled by pulling its rim.