A geothermal heat pump is a system that uses the stable temperature of the ground to heat and cool buildings. It works by transferring heat from the ground into a building during winter and moving heat from the building back into the ground during summer. This process is efficient and can significantly reduce energy costs. The system consists of a series of underground pipes, known as a ground loop, and a heat pump unit inside the building. By utilizing the earth's natural temperature, geothermal heat pumps provide a sustainable and environmentally friendly alternative to traditional heating and cooling methods.