angel vs archangel

angel and archangel both are nouns.

Word	Noun	Adjective	Verb	Adverb
angel	Yes	No	No	No
archangel	Yes	No	No	No

As nouns, archangel is a hyponym of angel; that is, archangel is a word with a more specific, narrower meaning than angel:

angel: spiritual being attendant upon God
archangel: an angel ranked above the highest rank in the celestial hierarchy

Other hyponyms of angel include cherub, seraph, guardian angel, guardian spirit, divine messenger.

angel (noun)	archangel (noun)
spiritual being attendant upon God	an angel ranked above the highest rank in the celestial hierarchy
someone who provides financial support for some venture	a biennial cultivated herb; its stems are candied and eaten and its roots are used medicinally
person of exceptional holiness