essential vs important

essential is a noun but important is not a noun.

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

essential (noun)	important (noun)
anything indispensable

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