historian vs annalist

historian and annalist both are nouns.

Word	Noun	Adjective	Verb	Adverb
historian	Yes	No	No	No
annalist	Yes	No	No	No

As nouns, annalist is a hyponym of historian; that is, annalist is a word with a more specific, narrower meaning than historian:

historian: a person who is an authority on history and who studies it and writes about it
annalist: a historian who writes annals

Other hyponyms of historian include art historian, chronicler.

historian (noun)	annalist (noun)
a person who is an authority on history and who studies it and writes about it	a historian who writes annals