small talk vs confab

small talk and confab both are nouns.

Word	Noun	Adjective	Verb	Adverb
small talk	Yes	No	No	No
confab	Yes	No	Yes	No

As nouns, confab is a hypernym of small talk; that is, confab is a word with a broader meaning than small talk:

Other hypernyms of small talk include chat, confabulation, schmoose, schmooze.

small talk (noun)	confab (noun)
light informal conversation for social occasions	an informal conversation

small talk (verb)	confab (verb)
	talk socially without exchanging too much information
	have a conference in order to talk something over