Chinese cabbage vs Brassica

Chinese cabbage and Brassica both are nouns.

Word	Noun	Adjective	Verb	Adverb
Chinese cabbage	Yes	No	No	No
Brassica	Yes	No	No	No

Chinese cabbage (noun)	Brassica (noun)
elongated head of crisp celery-like stalks and light green leaves	mustards: cabbages, cauliflowers, turnips, etc.
plant with an elongated head of broad stalked leaves resembling celery; used as a vegetable in east Asia