Geothermal power plants tap into the Earth's natural internal heat to generate electricity. They work similarly to conventional power plants by using geothermal heat instead of combustion to power steam turbines connected to generators. There are three main types - dry steam, flash steam, and binary cycle plants - which differ based on the temperature of the geothermal resource and method used to power the turbine. Geothermal energy is a renewable resource with advantages of being constant and not requiring fuel, but also has disadvantages of being location-restricted and carrying earthquake risks. It represents a growing industry that could help transition energy supplies to more sustainable sources.