do-gooder vs helper

do-gooder and helper both are nouns.

Word	Noun	Adjective	Verb	Adverb
do-gooder	Yes	No	No	No
helper	Yes	No	No	No

As nouns, helper is a hypernym of do-gooder; that is, helper is a word with a broader meaning than do-gooder:

do-gooder: someone devoted to the promotion of human welfare and to social reforms
helper: a person who helps people or institutions (especially with financial help)

Other hypernyms of do-gooder include benefactor.

do-gooder (noun)	helper (noun)
someone devoted to the promotion of human welfare and to social reforms	a person who helps people or institutions (especially with financial help)
	a person who contributes to the fulfillment of a need or furtherance of an effort or purpose