Routing transit number

A routing transit number (RTN) is a nine digit bank code, used in the United States, which appears on the bottom of negotiable instruments such as checks that identifies which financial institution it is drawn upon. This code is also used by the Automated Clearing House to process direct deposits and other automated transfers. The routing number is derived from the bank's transit number originated by the American Bankers Association, which designed it in 1910.
See more at Wikipedia.org...