The simple explanation of the difference between the two types is that DC motors run on direct current (DC) power supply and AC motors on alternating current (AC) power supply. In a DC power supply, the positive and negative polarities remain fixed. In an AC power supply, in contrast, the polarities cycle between positive and negative with a fixed cycle time. While both types of power supply can be used to rotate a motor, their differences influence the motor’s power, speed, and ease of control.