Robert W. Service vs writer

Robert W. Service and writer both are nouns.

Word	Noun	Adjective	Verb	Adverb
Robert W. Service	Yes	No	No	No
writer	Yes	No	No	No

Robert W. Service (noun)	writer (noun)
Canadian writer (born in England) who wrote about life in the Yukon Territory (1874-1958)	writes (books or stories or articles or the like) professionally (for pay)
	a person who is able to write and has written something