A Compressor is used to squeeze the Freon. On squeezing the pressure of the cool, low pressure gas Freon increases due to packing of the molecules, its temperature and energy also increases.
A Condenser helps to disperse the heat generated by the gas which comes outside the compressor. It is almost like a radiator inside the gas. The condenser has metal fins all around which helps in heat dissipation.
Evaporator Once the gas leaves the condenser its nature has changed from gas to liquid and it is much cooler. The liquid goes into the evaporator and its pressure drops and it again changes into gas. The liquid goes into the evaporator through a small narrow hole. On changing into gas it takes the heat from the air around it. This heat is required to change the liquid into gas. The evaporator is also provided with metal fins which help in heat exchange with the air surrounding it. From the evaporator the gas goes into the compressor again.