Compressed air, that is air compressed by an external force. Air is compressible. The air compressor does mechanical work to reduce its volume, accelerate molecular motion, and increase the pressure. The air is called compressed air.
Air occupies a certain space, but it has no fixed shape and volume. When pressure is applied to air in a closed container, the volume of air is compressed, increasing the internal pressure. When the external force is withdrawn, the air will return to its original volume under the action of the internal pressure.
Compressed air is an important power source. compared to other energy sources. It has the following obvious characteristics: clear and transparent, easy to transport, no special harmful properties. No danger of fire, not afraid of overloading. Can work in many unfavorable environments