viewing audience vs audience

viewing audience and audience both are nouns.

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

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

viewing audience: the audience reached by television
audience: the part of the general public interested in a source of information, entertainment, or a product/service

viewing audience (noun)	audience (noun)
the audience reached by television	a conference (usually with someone important)
	a gathering of spectators or listeners at a (usually public) performance
	the part of the general public interested in a source of information, entertainment, or a product/service
	an opportunity to state your case and be heard