Bank rate, also known as discount rate in American English, is the rate of interest which a central bank charges on its loans and advances to a commercial bank. The bank rate is known by a number of different terms depending on the country, and has changed over time in some countries as the mechanisms used to manage the rate have changed.Whenever a bank has a shortage of funds, they can typically borrow from the central bank based on the monetary policy of the country. The borrowing is commonly done via repos: the repo rate is the rate at which the central bank lends short-term money to the banks against securities. It is more applicable when there is a liquidity crunch in the market. In contrast, the reverse repo rate is the rate at which banks can park surplus funds with the reserve bank. This is mostly done when there is surplus liquidity in the market.