possessor vs doer

possessor and doer both are nouns.

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

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

Other hypernyms of possessor include actor, worker.

possessor (noun)	doer (noun)
a person who owns something	a person who acts and gets things done