existence vs universe

existence and universe both are nouns.

Word	Noun	Adjective	Verb	Adverb
existence	Yes	No	No	No
universe	Yes	No	No	No

As nouns, existence and universe are synonyms defined as:

Other synonyms of existence include cosmos, creation, macrocosm, world.

existence (noun)	universe (noun)
everything that exists anywhere	everything stated or assumed in a given discussion
the state or fact of existing	(statistics) the entire aggregation of items from which samples can be drawn
	everything that exists anywhere