The federal funds rate is the interest banks charge each other for overnight loans. Set by the Federal Reserve, it's a basis for other interest rates.

The Fed's decision will lower borrowing costs from a 23-year high as the central bank pivots to shoring up economic growth.

Having all but tamed inflation, the Federal Reserve is poised to do something Wednesday it hasn’t done in more than four years: Cut its benchmark interest rate, a step that should lead to lower borrowing costs for consumers and businesses.