writer vs John Philip Marquand

writer and John Philip Marquand both are nouns.

Word	Noun	Adjective	Verb	Adverb
writer	Yes	No	No	No
John Philip Marquand	Yes	No	No	No

writer (noun)	John Philip Marquand (noun)
writes (books or stories or articles or the like) professionally (for pay)	United States writer who created the Japanese detective Mr. Moto and wrote other novels as well (1893-1960)
a person who is able to write and has written something