[Mariachi]

The alternator creates current, converting mechanical energy into electrical energy
duh

The battery stores electrical energy.
once again, duh, but more specifically it stores chemical battery acid
cells that a connected in series in order to make 12 V by seperating a
difference in charge.

The battery and the alternator are in a parallel circuit. They do not operate
independently of each other.
really? I didn't know (sarcastic)

When the car is running, the alternator provides ALL the car's electrical needs,
including for the sound system. The battery DOES NOT.

if the voltage of the alternator goes below the voltage of the
battery, then the battery does supply current for whatever the
alternator cannot handle... unless you have a 75 amp alternator that
never needs to use the battery. But you are saying that you can have
50 amps going into my amplifier and my little 40 amp alternator will
supply all the current, which just doesn't make sense to me. If the
battery and alternator are in parallel, then I can see the alternator
taking over all the electrical systems when the current demand does
not exceed the limit of the alternator. But if the current demand
exceeds the limit of the alternator, you are saying the battery does
not take over at all, even though the battery is connected in parallel
with the alternator. I'm not saying you are wrong, i'm just asking if
the current demand exceeds the current supply limit of the alternator,
what happens then? Please explain...