pizza vs cheese pizza

pizza and cheese pizza both are nouns.

Word	Noun	Adjective	Verb	Adverb
pizza	Yes	No	No	No
cheese pizza	Yes	No	No	No

As nouns, cheese pizza is a hyponym of pizza; that is, cheese pizza is a word with a more specific, narrower meaning than pizza:

pizza: Italian open pie made of thin bread dough spread with a spiced mixture of e.g. tomato sauce and cheese
cheese pizza: pizza with lots of cheese

Other hyponyms of pizza include sausage pizza, pepperoni pizza, anchovy pizza, Sicilian pizza.

pizza (noun)	cheese pizza (noun)
Italian open pie made of thin bread dough spread with a spiced mixture of e.g. tomato sauce and cheese	pizza with lots of cheese