A routing number is a unique nine-digit code used in the United States to identify financial institutions. It helps facilitate the transfer of funds between banks, ensuring that money is sent to the correct location. Each bank has its own routing number, which can be found on checks or through the bank's website. Routing numbers are essential for various transactions, including direct deposits, wire transfers, and electronic payments. They help streamline the banking process by providing a clear way to direct funds, making it easier for customers to manage their finances with institutions like Bank of America or Wells Fargo.