A heat pump is a device that uses energy to transfer heat from one area to another. It works by compressing refrigerant to move thermal energy from a colder space to a warmer one. Heat pumps are typically used for heating and cooling buildings. They are an efficient way of transferring heat, as they require less energy than traditional heating methods such as electric resistance or natural gas furnaces. Heat pumps come in various sizes and designs, depending on the application and climate conditions.