Refrigeration is the process of removing heat from an enclosed space, or from a substance, to lower its temperature. A refrigerator uses the evaporation of a liquid to absorb heat. The liquid, or refrigerant, used in a refrigerator evaporates at an extremely low temperature, creating freezing temperatures inside the refrigerator. A liquid is rapidly vaporized (by means of compression) - the quickly expanding vapor thus requires kinetic energy and therefore draws the energy needed from the immediate area - which loses energy and becomes cooler. Cooling that is caused by the rapid expansion of gases is the primary means of refrigeration today.
