order Hemiptera vs class Insecta

order Hemiptera and class Insecta both are nouns.

Word	Noun	Adjective	Verb	Adverb
order Hemiptera	Yes	No	No	No
class Insecta	Yes	No	No	No

order Hemiptera (noun)	class Insecta (noun)
plant bugs, bedbugs, some true bugs; also includes suborders Heteroptera (true bugs) and Homoptera (e.g., aphids, plant lice and cicadas)	insects; about five-sixths of all known animal species