knower vs doer

knower and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
knower	Yes	No	No	No
doer	Yes	No	No	No

As nouns, doer is a hypernym of knower; that is, doer is a word with a broader meaning than knower:

Other hypernyms of knower include actor, worker.

knower (noun)	doer (noun)
a person who knows or apprehends	a person who acts and gets things done