user vs doer

user and doer both are nouns.

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

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

user: a person who makes use of a thing; someone who uses or employs something
doer: a person who acts and gets things done

Other hypernyms of user include actor, worker.

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

Other hypernyms of user include actor, worker.

user (noun)	doer (noun)
a person who makes use of a thing; someone who uses or employs something	a person who acts and gets things done
a person who uses something or someone selfishly or unethically
a person who takes drugs