angel vs seraph

angel and seraph both are nouns.

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

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

angel: spiritual being attendant upon God
seraph: an angel of the first order; usually portrayed as the winged head of a child

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

angel (noun)	seraph (noun)
spiritual being attendant upon God	an angel of the first order; usually portrayed as the winged head of a child
someone who provides financial support for some venture
person of exceptional holiness