class Aves vs order Columbiformes

class Aves and order Columbiformes both are nouns.

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

class Aves (noun)	order Columbiformes (noun)
(ornithology) the class of birds	sand grouse, pigeons, doves, extinct dodos and solitaires