class Aves vs order Trogoniformes

class Aves and order Trogoniformes both are nouns.

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

class Aves (noun)	order Trogoniformes (noun)
(ornithology) the class of birds	trogons