Samuel Langhorne Clemens vs writer

Samuel Langhorne Clemens and writer both are nouns.

Word	Noun	Adjective	Verb	Adverb
Samuel Langhorne Clemens	Yes	No	No	No
writer	Yes	No	No	No

Samuel Langhorne Clemens (noun)	writer (noun)
United States writer and humorist best known for his novels about Tom Sawyer and Huckleberry Finn (1835-1910)	writes (books or stories or articles or the like) professionally (for pay)
	a person who is able to write and has written something