What is fractional-reserve banking?

Banks create money by practising fractional-reserve banking in which banks keep only a fraction of their deposits in required reserve (normally 10% of the deposits) and lend out the remainder, while maintaining the simultaneous obligation to redeem all these deposits upon demand. Example, for every amount of deposit, the bank will loan out 90% of the deposit as excess reserve and keeping the remaining 10% as required reserve. This process is called multiple deposit creation or chequebook money. Each of the process of money multiplier ended when all excess reserve have been absorbed into required reserve.

Fractional reserve banking benefits the economy by providing regulators with powerful tools for manipulating the money supply and interest rates, which many see as essential to a healthy economy. It also can help the government to finance its debt.