important person vs actor

important person and actor both are nouns.

Word	Noun	Adjective	Verb	Adverb
important person	Yes	No	No	No
actor	Yes	No	No	No

As nouns, actor is a hypernym of important person; that is, actor is a word with a broader meaning than important person:

important person: a person whose actions and opinions strongly influence the course of events
actor: a person who acts and gets things done

Other hypernyms of important person include doer, worker.

important person (noun)	actor (noun)
a person whose actions and opinions strongly influence the course of events	a theatrical performer
	a person who acts and gets things done