A derivative (www.practicallaw.com/A34853) contract between two parties to exchange a series of cash flows for a stated period of time. Examples of swaps are the interest rate swap (www.practicallaw.com/A35440) and the currency swap (www.practicallaw.com/A34787).
For an overview on swaps, see Practice note, Derivatives: overview: Swap (www.practicallaw.com/8-385-8330).