How can refrigeration be defined?

Refrigeration can be defined as the process of lowering the temperature of a substance below that of its surroundings. This principle is fundamental to refrigeration systems, as they work to remove heat from a designated area or substance, allowing it to cool down effectively. The process relies on the transfer of thermal energy; by absorbing heat from a low-temperature environment and rejecting it to a higher temperature environment, refrigeration maintains desired low temperatures crucial for various applications, including food preservation and climate control.

The other definitions presented do not align with the concept of refrigeration. Increasing the temperature of a substance refers to heating, while maintaining temperature without energy loss does not specifically pertain to refrigeration, as the process often involves active energy use to operate refrigeration equipment. Finally, heating a substance to its boiling point is contrary to the cooling effect that refrigeration systems are designed to achieve.