Geothermal energy is a renewable energy source that harnesses the heat stored within the Earth's core to generate electricity and heat buildings. This energy can be accessed through geothermal power plants, where heat from deep within the Earth's crust is used to produce steam that drives turbines to generate electricity. Geothermal energy is considered sustainable and environmentally friendly, as it produces low levels of greenhouse gas emissions and does not rely on fossil fuels. It is a promising alternative to conventional energy sources and has the potential to reduce dependency on non-renewable resources.