INCREASES the pressure of the gas by REDUCING its volume. There are MAINLY four types of compressors.Rotary Screw CompressorReciprocating Air CompressorAxial CompressorCentrifugal CompressorIn the compressor, the rotating part is called the rotor. With the help of this rotor, the gases are generally fed into the less volume zone. As we know that pressure and volume both are inversely related to each other. When the same amount of gas is fed from a LARGE volume to a less volume zone. Its pressure get increases.