journalist vs author

journalist and author both are nouns.

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

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

journalist: a writer for newspapers and magazines
author: writes (books or stories or articles or the like) professionally (for pay)

Other hypernyms of journalist include writer.

journalist (noun)	author (noun)
a writer for newspapers and magazines	writes (books or stories or articles or the like) professionally (for pay)
someone who keeps a diary or journal	someone who originates or causes or initiates something

journalist (verb)	author (verb)
	be the author of