AC motors are electric motors which are powered by alternating current (AC). They are used to convert electrical energy into mechanical energy in order to do work in a system. Specifically, rotational energy is produced by utilizing the force of magnetic fields induced by alternating current flowing through electric coils. AC motors are used to provide power for a wide variety of systems, from small servomechanisms to large industrial machinery.
DC motors are electric motors that are powered by direct current (DC), such as from a battery or DC power supply. Their commutation can be brushed or brushless. The speed of a brushed DC motor can be controlled by changing the voltage alone. By contrast, an AC motor is powered by alternating current (AC) which is defined by both a voltage and a frequency.