Originally, the science of hydraulics covered the physical behavior of water at rest and in motion. The term has broadened its meaning to include the physical behavior of all liquids. This includes that area of hydraulics in which confined liquids are used under controlled pressure to do work. This area of hydraulics is sometimes referred to as power hydraulics. In order to safely and correctly operate a power hydraulic system, it is necessary to understand how the fluid behaves and why it behaves the way it does.Â
