illustration vs caption

illustration and caption both are nouns.

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

illustration (noun)	caption (noun)
a visual representation (a picture or diagram) that is used to make some subject more pleasing or easier to understand	brief description accompanying an illustration
an item of information that is typical of a class or group	translation of foreign dialogue of a movie or TV program; usually displayed at the bottom of the screen
artwork that helps make something clear or attractive	taking exception; especially a quibble based on a captious argument
showing by example

illustration (verb)	caption (verb)
	provide with a caption, as of a photograph or a drawing