William Sydney Porter vs writer

William Sydney Porter and writer both are nouns.

Word	Noun	Adjective	Verb	Adverb
William Sydney Porter	Yes	No	No	No
writer	Yes	No	No	No

William Sydney Porter (noun)	writer (noun)
United States writer of short stories whose pen name was O. Henry (1862-1910)	writes (books or stories or articles or the like) professionally (for pay)
	a person who is able to write and has written something