obliger vs benefactor

obliger and benefactor both are nouns.

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

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

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

Other hypernyms of obliger include helper.

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