sparer vs helper

sparer and helper both are nouns.

Word	Noun	Adjective	Verb	Adverb
sparer	Yes	No	No	No
helper	Yes	No	No	No

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

sparer: someone who refrains from injuring or destroying
helper: a person who helps people or institutions (especially with financial help)

Other hypernyms of sparer include benefactor.

sparer (noun)	helper (noun)
someone who refrains from injuring or destroying	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