What is the definition of hydraulics and pneumatics?

Machines of all types need power. Power allows the machines to do specific kinds of work. Two of the most efficient and compact forms of power for machines are hydraulic and pneumatic systems. Hydraulics and pneumatics can be configured into different types of power sources to lift, lower, pull, push, turn, rotate and move machines carrying tremendous loads. Tools can also be powered to break stone, join steel and cut wood. Hydraulics and pneumatics provide the energy to make work happen.