china vs willowware

china and willowware both are nouns.

Word	Noun	Adjective	Verb	Adverb
china	Yes	No	No	No
willowware	Yes	No	No	No

As nouns, willowware is a hyponym of china; that is, willowware is a word with a more specific, narrower meaning than china:

china: dishware made of high quality porcelain
willowware: chinaware decorated with a blue Chinese design on a white background depicting a willow tree and often a river

Other hyponyms of china include willow-pattern.

china (noun)	willowware (noun)
high quality porcelain originally made only in China	chinaware decorated with a blue Chinese design on a white background depicting a willow tree and often a river
dishware made of high quality porcelain