A turbine is a rotary engine that extracts energy from a fluid flow and converts it into useful work.It converts the energy of rushing water, steam or wind into mechanical energy to drive a generator.Then generator produce electricity with mechanical energy given by turbine.
Turbine type according to available head
Propeller up to 15 metres
Kaplan up to 30 metres
Francis 10 to 300 metres
Pelton 300 metres and over