Fluid power is the generation, regulation, and transmission of power may all be accomplished by the use of fluids under pressure through a process. Fluid power may be further separated into hydraulics, which makes use of a liquid like mineral oil or water, and pneumatics, which makes use of a gas like air or other gases. Both types of fluid power are referred to as "fluid" power. Fluid power systems are often contained inside a single structure or mobile machine nowadays, although in the past they were utilised to transport power from a central source to industrial users across extensive geographic regions using compressed air and water pressure systems.
Fluid power systems do their function by using a pressurised fluid that bears directly on a piston that is housed inside a cylinder or within a fluid motor. A fluid cylinder generates a force, which in turn results in linear motion, while a fluid motor generates torque, which in turn results in rotating motion. Cylinders and motors, which are often referred to as actuators, are the components of a fluid power system that are responsible for carrying out the necessary work. Control components like valves are responsible for regulating the operation of the system.