What is the purpose of a compressor in a refrigeration cycle?

In a refrigeration cycle, the compressor plays a crucial role by raising the pressure and temperature of the refrigerant gas. When the refrigerant enters the compressor, it is typically at a low pressure and temperature. The compressor then compresses this low-pressure vapor into a high-pressure vapor by significantly decreasing the volume of the gas. This not only increases the pressure but also elevates the temperature of the refrigerant due to the principles of thermodynamics, specifically the ideal gas law.

The high-pressure, high-temperature gas is then routed to the condenser, where it releases heat and changes states from vapor to liquid, completing the cycle. This process is essential for the refrigeration system to function effectively, allowing it to absorb heat from the designated areas (like a refrigerator or air conditioner) and expel it outside, thereby achieving cooling.

The other options pertain to different components or functions within refrigeration systems, such as heat absorption or air circulation, which do not accurately describe the specific role of the compressor.