By a direct current motor we understand an electric motor which is operated with direct current. This consists of an immobile outer part, the stator, and a rotating inner part set in bearings, the rotor. In the conventional smaller direct current motors, the stator consists of a permanent magnet.

The armature winding is connected via the commutator. The polarity of the direct current defines the direction in which the motor will rotate. The contacts ("brushes") of the commutator are so designed that during rotation, they are continuously changing the polarity of the armature winding. They are made of a material which is a good electrical conductor, and which wears slightly during operation, thus effectively being self-lubricating (most of these materials contain graphite and copper dust).

Good starting performance and controllability are among the advantages of the direct current motor. 

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