The DC-motor takes a direct current (hence the name) and rotates in either direction depending on the polarity of the voltage. The DC-motor rotates continuously with many revelations per second (RPM). Application is therefore often related to rapid or great general movement, such as propelling RC cars forward, since control of the motor is restricted to direction and speed of rotation only. The motor should be powered appropriately to avoid blowback to a GPIO, and to provide sufficient power.

Links:

Setup guide with DC motor and Arduino