propagation vs public exposure

propagation and public exposure both are nouns.

Word	Noun	Adjective	Verb	Adverb
propagation	Yes	No	No	No
public exposure	Yes	No	No	No

As nouns, public exposure is a hypernym of propagation; that is, public exposure is a word with a broader meaning than propagation:

propagation: the spreading of something (a belief or practice) into new regions
public exposure: the opening of a subject to widespread discussion and debate

Other hypernyms of propagation include airing, dissemination, spreading.

propagation (noun)	public exposure (noun)
the act of producing offspring or multiplying by such production	the opening of a subject to widespread discussion and debate
the spreading of something (a belief or practice) into new regions
the movement of a wave through a medium