instance vs illustration

instance and illustration both are nouns.

Word	Noun	Adjective	Verb	Adverb
instance	Yes	No	Yes	No
illustration	Yes	No	No	No

As nouns, instance and illustration are synonyms defined as:

instance and illustration: an item of information that is typical of a class or group

Other synonyms of instance include example, representative.

instance (noun)	illustration (noun)
an item of information that is typical of a class or group	a visual representation (a picture or diagram) that is used to make some subject more pleasing or easier to understand
an occurrence of something	an item of information that is typical of a class or group
	artwork that helps make something clear or attractive
	showing by example

instance (verb)	illustration (verb)
clarify by giving an example of