The compressor is regarded as the heart of the refrigeration system, and the specialized term that best represents the characteristics of the compressor is called the "vapor pump". The actual responsibility of the compressor is to increase the pressure and raise the suction pressure state to the discharge pressure state.

The specifications of compressors are divided according to input power. Generally, there is a difference of about 50W between each specification. Additionally, there are also classifications based on cylinder volume.