class Hexapoda vs order Orthoptera

class Hexapoda and order Orthoptera both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Hexapoda	Yes	No	No	No
order Orthoptera	Yes	No	No	No

class Hexapoda (noun)	order Orthoptera (noun)
insects; about five-sixths of all known animal species	grasshoppers and locusts; crickets