audience vs multitude

audience and multitude both are nouns.

Word	Noun	Adjective	Verb	Adverb
audience	Yes	No	No	No
multitude	Yes	No	No	No

As nouns, multitude is a hypernym of audience; that is, multitude is a word with a broader meaning than audience:

audience: the part of the general public interested in a source of information, entertainment, or a product/service
multitude: the common people generally

Other hypernyms of audience include hoi polloi, mass, masses, people, the great unwashed.

audience (noun)	multitude (noun)
a conference (usually with someone important)	a large gathering of people
a gathering of spectators or listeners at a (usually public) performance	the common people generally
the part of the general public interested in a source of information, entertainment, or a product/service	a large indefinite quantity
an opportunity to state your case and be heard