class Aves vs order Strigiformes

class Aves and order Strigiformes both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Aves	Yes	No	No	No
order Strigiformes	Yes	No	No	No

class Aves (noun)	order Strigiformes (noun)
(ornithology) the class of birds	owls