In physics, dynamics is the branch of classical mechanics that is concerned with the motion of bodies. It is divided into two branches called kinematics and kinetics. Kinematics is concerned with the space-time relationship of a given motion without considering the origins of forces. In other words, it only deals with the geometric aspect of motion. Kinetics is concerned with the motion of bodies under the action of given forces. On the other hand, statics is concerned with rigid bodies at rest. In quantum physics, dynamics may refer to how forces are quantized, as in quantum electrodynamics or quantum chromodynamics.