An electric motor is an electric machine that transforms electrical energy into mechanical energy through electromagnetic interactions. Some of the electric motors are reversible, they can transform mechanical energy into electrical energy working as generators. Electric traction motors used in locomotives often perform both tasks if equipped with regenerative brakes.
They are widely used in the typical industrial gear box, commercial and private installations. They can be connected to a power supply or battery operated. Thus, in cars they are starting to be used in hybrid vehicles to take advantage of the advantages of both.