What is the process called that involves the transmission and control of energy using a pressurized fluid?

The process of transmitting and controlling energy using pressurized fluid is most commonly referred to as fluid power. Fluid power encompasses both hydraulics and pneumatics, but the term specifically highlights the broader application of using fluids—liquids or gases—to perform work through pressure and flow.

Hydraulics specifically deals with the use of liquids, typically oil or water, to transmit force and energy. Pneumatics, on the other hand, involves the use of gases, usually air. While both hydraulics and pneumatics fall under the umbrella of fluid power, selecting fluid power as the answer recognizes the entire system of energy transmission and control that can include either type of fluid.

Pressure control does not encompass the entire process, as it focuses solely on the regulation of pressure within a system rather than the broader application of transmitting and controlling energy through pressurized fluids. Thus, fluid power is the most encompassing and accurate term for this process.