I used to work at Domino's.  It's a classic American Pizza chain.  Although pizza was invented in Naples.
I would have eaten so much pizza. Ive heard of something called Neapolitan pizza. Is that something different?
Indeed it is.  It's a form of pizza made specifically with Tomatoes and Mozzarella Cheese.
I would love to go to Naples and eat some authentic Neapolitan pizza. 
Me too.  It's actually a bigger city than I thought.  Over 3 million people!  It's actually the 9th most populated city in the EU.
Oh wow. Is pizza popular anywhere else besides Naples and the United States?
Well you could say it's popular everywhere it's known.  There was a precursor to pizza called "panis focacius" where they would take bread and add toppings to it.