chooser vs doer

chooser and doer both are nouns.

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

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

Other hypernyms of chooser include actor, worker.

chooser (noun)	doer (noun)
a person who chooses or selects out	a person who acts and gets things done