Final answer:
Starter motors utilize shunt coil winding and movable pole shoes for engine cranking, with brushes ensuring the current direction is correct for continual rotation.
Step-by-step explanation:
Starter motors in vehicles use the shunt coil winding and a movable pole shoe to engage the starter drive and crank the engine. The process involves a coil within the motor that rotates in a magnetic field. To maintain the rotation in a single direction, the current in the coil must be reversed at precise times during the rotation. This reversal is achieved with the use of automatic switches known as brushes, in coordination with a component called a commutator. As mentioned in the context, if mechanical energy is instead applied to force the coil to rotate against the magnetic field, the device acts as a generator, converting mechanical energy to electrical energy. This phenomenon is based on Faraday's law of electromagnetic induction.