Control system
In control and electrical engineering, a control system is an interconnection between two systems which are referred to as the plant and the controller. The plant is the system which is to be controlled (whose behavior is to be controlled or "shaped") while the controller is the system that does the controlling and implements the control action. An interconnection between the plant and controller serves to couple the dynamics of the two systems and is usually achieved by feeding some signals from the plant into the controller and vice versa. In practice, the term system refers to a causal (non-anticipating) dynamical system with causality roughly meaning that no signal in the system which is functionally dependent on a set of other signals in the system can depend on the future values of the latter signals, but only on their past values. Causality is a natural characteristic of physical systems since no such systems would be able to predict the future.