obliger vs helper

obliger and helper both are nouns.

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

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

obliger: someone who performs a service or does a favor
helper: a person who helps people or institutions (especially with financial help)

Other hypernyms of obliger include benefactor.

obliger (noun)	helper (noun)
someone who performs a service or does a favor	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