This force and motion maybe in the form of pushing, pulling, rotating, regulating, or driving.
Fluid power includes hydraulics, which involves liquids, and pneumatics, which involves gases.
Liquids and gases are similar in many respects. The differences are pointed out in the appropriate areas of this manual. This manual presents many of the fundamental concepts in the fields of hydraulics and pneumatics. It is intended as a basic reference for all personnel of the Navy whose duties and responsibilities require them to have a knowledge of the fundamentals of fluid power. Consequently, emphasis is placed primarily on the theory of operation of typical fluid power systems and components that have applications in naval equipment.