city vs Sheffield

city and Sheffield both are nouns.

Word	Noun	Adjective	Verb	Adverb
city	Yes	No	No	No
Sheffield	Yes	No	No	No

city (noun)	Sheffield (noun)
people living in a large densely populated municipality	a steel manufacturing city in northern England famous for its cutlery industry
a large and densely populated urban area; may include several independent administrative districts
an incorporated administrative district established by state charter