dialogue vs bargaining

dialogue and bargaining both are nouns.

Word	Noun	Adjective	Verb	Adverb
dialogue	Yes	No	No	No
bargaining	Yes	No	No	No

As nouns, bargaining is a hyponym of dialogue; that is, bargaining is a word with a more specific, narrower meaning than dialogue:

dialogue (noun)	bargaining (noun)
the lines spoken by characters in drama or fiction	the negotiation of the terms of a transaction or agreement
a conversation between two persons
a literary composition in the form of a conversation between two people
a discussion intended to produce an agreement