important vs essential

important is not a noun while essential is a noun.

Word	Noun	Adjective	Verb	Adverb
important	No	Yes	No	No
essential	Yes	Yes	No	No

important (noun)	essential (noun)
	anything indispensable

important (adjective)	essential (adjective)
of great significance or value	basic and fundamental
of extreme importance; vital to the resolution of a crisis	defining rights and duties as opposed to giving the rules by which rights and duties are established
important in effect or meaning	being or relating to or containing the essence of a plant etc
having or suggesting a consciousness of high position	of the greatest importance
having authority or ascendancy or influence	absolutely necessary; vitally necessary