Question isn't clear. A hydraulic cylinder is one tube inside of another tube. Fluid is pumped into the larger one under pressure and this forces the smaller inside one to extend. It doesn't have to be fluid, an impact wrench or air drill is the same principal using air.
Pascals
Hydraulic system make use of hydraulic devices to perform a variety of functions.
hydraulic car lift and hydraulic tire changer
Archimedes' Principle
hydraulic systems
Devices such as hydraulic lifts, hydraulic brakes in vehicles, hydraulic jacks, and hydraulic presses utilize Pascal's principle. This principle states that a change in pressure applied to an enclosed fluid is transmitted undiminished to all portions of the fluid and to the walls of its container.
There are more than two hydraulic devices that an auto machanic is familiar with but one of the is the braking system of a car and the other is the automatic transmissions of a car.
dentist's chair and brakes of a car
Hydraulic power can generate large force and we do our jobs better and faster. As such devices. Loader. Hydraulic jack. Car brake.
A car lift and a jack
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