Geothermal energy is a renewable energy source that harnesses heat from the Earth's interior. This heat can be found in hot water and steam reservoirs beneath the surface, which can be used for electricity generation or direct heating applications. Geothermal power plants convert this thermal energy into electricity, making it a sustainable alternative to fossil fuels. In addition to electricity generation, geothermal energy can be used for heating buildings, growing plants in greenhouses, and drying crops. Countries like Iceland and the United States have successfully utilized geothermal resources, demonstrating its potential as a reliable energy source.