Compression refrigeration is a process used to cool spaces or preserve food by removing heat. It works by compressing a refrigerant gas, which raises its temperature and pressure. The hot gas then passes through a condenser, where it releases heat and turns into a liquid. This liquid refrigerant then expands, lowering its pressure and temperature, allowing it to absorb heat from the surrounding area. The cycle continues as the cold refrigerant evaporates, absorbing heat from the environment, and returns to the compressor as a gas. This method is commonly used in refrigerators, air conditioners, and freezers to maintain desired temperatures.