initiator vs leader

initiator and leader both are nouns.

Word	Noun	Adjective	Verb	Adverb
initiator	Yes	No	No	No
leader	Yes	No	No	No

As nouns, leader is a hypernym of initiator; that is, leader is a word with a broader meaning than initiator:

initiator (noun)	leader (noun)
a person who initiates a course of action	a featured article of merchandise sold at a loss in order to draw customers
	a person who rules or guides or inspires others