Central bank money is the technical Bundesbank term used to refer to money that can only be created by a central bank. Central bank money comprises the coins and banknotes that the central bank brings into circulation as well as the sight deposits held by third parties at the central bank. The sight deposits that commercial banks hold with the central bank are particularly important in this context. First, they are used for the settlement of payment transactions. Second, by having these deposits, the commercial banks are satisfying their obligation to hold "minimum reserves" with the central bank. Central bank money is also referred to as "monetary base", "base money", "high-powered money" or, for short, M0 ("M-zero"), and occasionally as "reserves" or "reserve holdings" (however, the definitions of these terms can vary slightly). Although we talk about central banks providing "liquidity" to or withdrawing "liquidity" from commercial banks, we are actually referring to the provision and withdrawal of central bank money.