Answer:
Both are correct.
Explanation:
Alternator creates alternating current that is rectified to direct current. Supplies about 13.5 volts to charge a 12 volt battery. Alternator is spinning when engine is running, belt driven.
Starter motor engages a pinion gear that is spun by the direct current electrical field. Gear spins the flywheel on the automotive engine. Drops out once engine is running.