This document provides an overview of geothermal technology. It explains that geothermal systems use the constant temperature below the earth's surface to heat and cool homes via a network of underground pipes. Water circulating through these pipes absorbs or releases heat, which is transferred via heat pump to interior spaces. These systems have many benefits like lower utility bills, reduced maintenance, comfort, and environmental conservation. While initial costs may be higher, geothermal has the lowest lifetime costs and many rebates are available. It is an increasingly popular option for both residential and commercial buildings. Proper installation by a certified professional is important.