affairs vs transaction

affairs and transaction both are nouns.

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

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

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

Other hypernyms of affairs include dealing, dealings.

affairs (noun)	transaction (noun)
transactions of professional or public interest	the act of transacting within or between groups (as carrying on commercial activities)
matters of personal concern