Throughout this site we use many technical terms, and given the breadth of readership our site enjoys, sometimes we are remiss and incorrectly assume everyone knows what we are referring to. For those that do not, here are some explanations of the technical terms use.
Copper segments, separated by insulating strips, fitted to a drum and connected to the armature coils of a DC generator or motor. In a dynamo, carbon brushes bearing against the segments carry the electrical current generated by the dynamo to the battery. In a motor, electrical energy from the battery is carried through the brushes to the commutator to drive the motor.