While both A.C. and D.C. motors serve the same function of converting electrical energy into mechanical energy, they are powered, constructed and controlled differently. The most basic difference is the power source. A.C. motors are powered from alternating current (A.C.) While D.C. motors are powered from direct current (D.C.).

With direct current, energy is obtained from batteries or cells and generates a constant voltage.  This constant voltage then stimulates the steady flow of electrons in one direction.  It is this constant and precise flow of energy that makes direct current most suitable for applications that require precise and stable operation, such as speed and torque control applications.

With alternating current, energy is obtained through both AC generators and mains to generate a varying voltage.  It is because of this varying voltage that the electrons of an alternating current, unlike those of a direct current, continuously change direction, moving forward and backward.  Also in contrast to direct current, which is unable to produce voltage capable of traveling over long distances, the voltage of alternating current is safe to transfer over long distance and provide greater power, making alternating current ideal for both home and industrial applications.