Coleoptera vs class Insecta

Coleoptera and class Insecta both are nouns.

Word	Noun	Adjective	Verb	Adverb
Coleoptera	Yes	No	No	No
class Insecta	Yes	No	No	No

Coleoptera (noun)	class Insecta (noun)
beetles	insects; about five-sixths of all known animal species