class Insecta vs Arthropoda

class Insecta and Arthropoda both are nouns.

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

class Insecta (noun)	Arthropoda (noun)
insects; about five-sixths of all known animal species	jointed-foot invertebrates: arachnids, crustaceans, insects, millipedes, centipedes