An Interest Rate Swap (IRS) is a derivative financial instrument that allows two parties to exchange predetermined cash flows based on interest rate benchmarks. It is essentially an agreement between two parties to exchange interest rate payments based on a notional amount for a set period of time.

The purpose of an Interest Rate Swap is to manage interest rate risk. If one party has a variable interest rate (such as a floating interest rate linked to a benchmark like the London Interbank Offered Rate or LIBOR), they may want to convert it to a fixed interest rate. The other party, who has a fixed interest rate, may wish to have a variable interest rate. By entering into an IRS agreement, both parties can achieve their desired interest rate exposure.

Interest Rate Swaps are commonly used by financial institutions, corporations, and governments. For example, a company with floating rate debt may enter into an IRS agreement to protect itself from rising interest rates. A bank may also use an IRS to manage interest rate risk on its balance sheet or to generate income from trading activities.

Overall, Interest Rate Swaps are an important tool for managing risk and achieving desired interest rate exposure in the financial industry. They are widely used and have become an integral part of modern financial markets.