Kinematics (from Greek κινεῖν, kinein, to move) is the branch of classical mechanics or mechanical engineering that describes the motion of bodies (objects) and systems (groups of objects) without consideration of the forces that cause the motion. Kinematics can be used to find the possible range of motion for a given mechanism, or, working in reverse, can be used to design a mechanism that has a desired range of motion. The movement of a crane and the oscillations of a piston in an engine are both simple kinematic systems.