dialogue vs talking

dialogue and talking both are nouns.

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

As nouns, talking is a hypernym of dialogue; that is, talking is a word with a broader meaning than dialogue:

Other hypernyms of dialogue include talk.

dialogue (noun)	talking (noun)
the lines spoken by characters in drama or fiction	an exchange of ideas via conversation
a conversation between two persons
a literary composition in the form of a conversation between two people
a discussion intended to produce an agreement