The term Geothermal originates from two Geek words 'GEO' and 'THERM'. The Greek word ‘geo’ meant the earth whilst their word for ‘therm’ meant heat from the earth.
Energy that is stored in earth is called a Geothermal energy. Geothermal energy is extracted from the head obtained in earth’s core. This is one of clean sources of energy because it releases little greenhouse gases. Geothermal energy is natural source of energy.