A motor is a device that converts electrical energy into mechanical energy. It works by converting electrical energy into mechanical energy when a current passes through a wire wound around a metal cylindrical core, known as a rotor. The rotor is set in motion by the magnetic field created by the current. The current flowing through the wire coil causes the rotor to spin, which in turn induces an electromotive force (EMF) in the coil. This EMF opposite in polarity to the current that caused it and is known as a back EMF. The back EMF opposes the original current, causing the motor to run more efficiently.