A tractor's hydraulic system is a power-transfer mechanism. It uses pressurised fluid to transfer power to heavy parts. It simply converts engine power to fluid pressure to enable the tractor to move heavy loads. 

The Basic Mechanism of Hydraulics System of a Tractor

• The engine-driven pump forces oil out of a tank and into the system.

• The valves are the control centre. Moving a lever opens a valve that sends the oil where you want it to go.

• The actuators are the motors or cylinders. When oil at high pressure hits a piston, it makes it move.

Key Functions of a Tractor Hydraulic System

• Steering & Braking: It makes turning a multi-ton machine effortless by providing "power" assistance.

• Lifts Implements: It makes the three-point hitch work so that the tractor can lower or raise implements.

• Powers Attachments: It gives front-end loaders and tipping trailers the power they need to work.

By using Pascal’s Law, the hydraulic system of a tractor multiplies a small amount of effort into tons of force. Hence, a single operator can control heavy implements with just a few light touches on a control stick.