Electric motors use either AC (alternating current) or DC (direct current) to convert electronic energy into mechanical energy. These two types of electric motors are designed and constructed differently and generate and transform energy in different ways. A decent grasp of electricity and how it works is necessary to understand how alternating current and direct current motors are different. Electricity, unlike light or heat, is not commonly found in nature. An electric current is created by the movement of electrons along a conductor. The terms alternating current and direct current refer to the direction the electrons move along the conductor.