ability vs knowledge

ability and knowledge both are nouns.

Word	Noun	Adjective	Verb	Adverb
ability	Yes	No	No	No
knowledge	Yes	No	No	No

As nouns, knowledge is a hypernym of ability; that is, knowledge is a word with a broader meaning than ability:

ability: possession of the qualities (especially mental qualities) required to do something or get something done
knowledge: the psychological result of perception and learning and reasoning

Other hypernyms of ability include cognition, noesis.

ability (noun)	knowledge (noun)
the quality of being able to perform; a quality that permits or facilitates achievement or accomplishment	the psychological result of perception and learning and reasoning
possession of the qualities (especially mental qualities) required to do something or get something done