biographer vs author

biographer and author both are nouns.

Word	Noun	Adjective	Verb	Adverb
biographer	Yes	No	No	No
author	Yes	No	Yes	No

As nouns, author is a hypernym of biographer; that is, author is a word with a broader meaning than biographer:

biographer: someone who writes an account of a person's life
author: writes (books or stories or articles or the like) professionally (for pay)

Other hypernyms of biographer include writer.

biographer (noun)	author (noun)
someone who writes an account of a person's life	writes (books or stories or articles or the like) professionally (for pay)
	someone who originates or causes or initiates something

biographer (verb)	author (verb)
	be the author of