auxiliary vs helper

auxiliary and helper both are nouns.

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

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

auxiliary: someone who acts as assistant
helper: a person who contributes to the fulfillment of a need or furtherance of an effort or purpose

Other hypernyms of auxiliary include assistant, help, supporter.

auxiliary (noun)	helper (noun)
someone who acts as assistant	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

auxiliary (adjective)	helper (adjective)
functioning in a supporting capacity
furnishing added support