writer vs Margaret Mitchell

writer and Margaret Mitchell both are nouns.

Word	Noun	Adjective	Verb	Adverb
writer	Yes	No	No	No
Margaret Mitchell	Yes	No	No	No

writer (noun)	Margaret Mitchell (noun)
writes (books or stories or articles or the like) professionally (for pay)	United States writer noted for her novel about the South during the American Civil War (1900-1949)
a person who is able to write and has written something