class Chlorophyceae vs order Ulvales

class Chlorophyceae and order Ulvales both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Chlorophyceae	Yes	No	No	No
order Ulvales	Yes	No	No	No

class Chlorophyceae (noun)	order Ulvales (noun)
algae distinguished chiefly by having flagella and a clear green color, their chlorophyll being masked little if at all by other pigments	an order of protoctist