A hydraulic machine works by applying force to an incompressible fluid, which then transfers this force to another point. The simplest machines usually consist of an oil-filled container and two pistons. One piston applies force to the liquid, which in turn transfers it to the other piston.
People use many types of hydraulic machines every day—press machines, auto brakes and even snow ploughs. From log splitters to pumps, hydraulic machines are important tools that keep the world moving.