talking vs dialogue

talking and dialogue both are nouns.

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

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

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