As far as the control of hydraulic systems is concerned, a distinction must be made — since the term "control" is rather a general one — between control in the signal range and control in the power section.
The power section in a system comprises all the components within a circuit which influence the transmission of energy from the pump to the loads (Figure L 17). As such, the power section in a hydraulic system only contains hydraulic components.
Figure L 17: Power and signal section