The refrigeration cycle consists of 4 main components. They are the compressor, condenser, thermal expansion valve and evaporator.
Compressor
Helps to circulate the refrigerant throughout the system, akin to the beatting heart of a human. The temperature increases as pressure increases due to the compressor.
Condenser
Heat exchange with external surrounding air or liquid to cool down the refrigerant.
Thermal expansion valve
Helps to maintain a pressure difference. As the refrigerant moves from an area of higher pressure to lower pressure, the temperature also decreases.
Evaporator
Heat exchange to transfer heat out of e.g. a room, AHU.
(Updated: )