Principles of pneumatics are the same as hydraulics, the main difference is that pneumatics uses a gas to transmit power.
Compressed air is the main type of gas used in pneumatics. Nitrogen and other inert gases can also be used for certain applications.
Most operate at 100 PSI or less
Advantages: components are lightweight due to lower pressure, pneumatic systems offer "give", simpler design because air can be exhausted to the atmosphere, and pick and place of delicate objects (using a vacuum to pick up a sheet of paper)
These systems are used widely in factory automation, medical and food processing equipment. They are also used for off- and on-highway vehicle systems.