The Federal Reserve (the Fed) plays a crucial role in shaping the U.S. economy, and one of its most powerful tools is the federal funds rate. Although the Fed's rate doesn't directly determine mortgage rates, it has an indirect but significant impact on them. Understanding how this works can help you make better decisions when buying a home or refinancing a mortgage. What Is the Federal Funds Rate?The federal funds rate is the interest rate at which banks lend money to each other overnight to me…