class Aves vs order Anseriformes

class Aves and order Anseriformes both are nouns.

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

class Aves (noun)	order Anseriformes (noun)
(ornithology) the class of birds	ducks, geese, swans, screamers