A steam turbine is a device that converts the energy from steam into mechanical energy. It works by directing high-pressure steam onto blades attached to a rotor, causing it to spin. This spinning motion can then be used to generate electricity or power machinery. Steam turbines are commonly used in power plants, where they play a crucial role in generating electricity from sources like coal, natural gas, or nuclear energy. They are efficient and can produce large amounts of power, making them an essential component in modern energy production systems.