I think the reason why I can't understand this is because I don't really understand what goes on in the auto transmission. It's a black box to me.

When you're in park, I know there's a parking pawl that prevents the wheels from rotating. So if you're in park and you rev the car, how are you not:

A) Damaging the pawl by attempting the move the car?
B) Not overheating as if you're stuck in snow and trying to drive out?

I think the answer would be if you're in Park, the connection from engine to transmission is disconnected so:

A) There's no pressure put on the pawl.
B) There's no overheating since the connection from engine to transmission is disconnected so the engine is revving by itself. You burn up the transmission trying to drive out of snow because you're in Drive, the wheels aren't moving and you're revving as opposed to Park, the wheels aren't moving and you're revving.

So is Park then the same as Neutral but with the pawl used so the car doesn't move? Logically I think so, but I don't know. Is there any source that proves what happens when you're in Park and why it's considered safe to rev (as long as you're not at redline) while in Park or Neutral? I'm not wondering this because I want to annoy people by revving my car in my driveway. I need to rev it for times like bleeding coolant and I wonder if I damage the transmission in anyway. I'm not worried about the engine, I'm worried about the transmission.

 

Long story short, yes, Park and Neutral are the same except for the pawl.

 

Yes it is the same as being in Neutral.

You will be fine.