Factory ammeter

No ALL the vr does is maintain proper output voltage. If the alternator is a 30, 40, 60, 180, it can put out that amperage if the battery is low enough, AKA after the lights been left on, or if there are a lot of accessories, IE electric pumps, fans, big stereo, whatever.
So the alt only puts out the amps needed to maintain the battery? For example it will put out more amps if the battery is low charge vs full charge?