affairs vs dealing

affairs and dealing both are nouns.

Word	Noun	Adjective	Verb	Adverb
affairs	Yes	No	No	No
dealing	Yes	No	No	No

As nouns, dealing is a hypernym of affairs; that is, dealing is a word with a broader meaning than affairs:

affairs: transactions of professional or public interest
dealing: the act of transacting within or between groups (as carrying on commercial activities)

Other hypernyms of affairs include dealings, transaction.

affairs (noun)	dealing (noun)
transactions of professional or public interest	method or manner of conduct in relation to others
matters of personal concern	the act of transacting within or between groups (as carrying on commercial activities)