Identifying what type of motor component is described: a rotating part constructed of laminated steel core containing current-carrying copper wires.

The description given in the question pertains specifically to the armature windings of a motor. The armature is a key component in both AC and DC motors, typically made of laminated steel to reduce energy losses due to eddy currents. The laminated steel core provides structural support and helps improve the efficiency of the motor by minimizing these losses.

These armature windings are where the current-carrying copper wires are located, creating a magnetic field when electric current flows through them. This magnetic field interacts with the magnetic field produced by other components, such as the stator, causing the rotor to turn and thereby converting electrical energy into mechanical energy.

Other provided options refer to different components of the motor that do not encapsulate the specific characteristics described. The stator, for instance, houses the armature and does not contain the winding of the wires itself. The commutator's role is to ensure the current direction in the windings changes, while brushes are used to make contact with the commutator; neither of these options involves the process of conducting current through windings as described.