I think it is you who are making it more confusing that it needs to be. So
again, let's try to unconfuse this by going back to my very simple
question. When you plug it in, how many bulbs light up?

Just answer that, nothing more. You're getting yourself all confused on
the other terminology which is confusing everyone else in the process and
making this one very convulted thread on what should have been a very
simple question.

Tell me what I don't know, not what is already obvious...

what do you call a bulb??? What I see is two bulbs, but they are connected,
so that's one bulb.... see, I can be confusing and confused all at the same
time....