Alternator: Device that generates the electric current that charges the battery.
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It can be found next to the engine and it is activated by the poly-V belt. While the engine is running, the alternator will charge the battery. Inside of it there is a voltage regulator that limits the electric tension that will be delivered.
If the starter just 'spins' it indicates a solenoid issue. You could try 'jumping' the ignition terminal to the power post on the solenoid with a screwdriver...if it still just 'spins' the solenoid is bad. If this starts the car, then it's likely just an ignition fuse. Consult your owners manual for the location as there can be multiple fuses related to the ignition system.