fortification vs prowess

fortification and prowess both are nouns.

Word	Noun	Adjective	Verb	Adverb
fortification	Yes	No	No	No
prowess	Yes	No	No	No

As nouns, prowess is a hypernym of fortification; that is, prowess is a word with a broader meaning than fortification:

fortification: the art or science of strengthening defenses
prowess: a superior skill that you can learn by study and practice and observation

Other hypernyms of fortification include art, artistry.

fortification (noun)	prowess (noun)
the addition of an ingredient for the purpose of enrichment (as the addition of alcohol to wine or the addition of vitamins to food)	a superior skill that you can learn by study and practice and observation
defensive structure consisting of walls or mounds built around a stronghold to strengthen it
the art or science of strengthening defenses