Money is any instrument that constitutes a unit of account, a store of value and a means of payment. It must serve these three functions simultaneously (see What can we do with money?). Money has changed over time. Nowadays, it consists of coins, banknotes and bank deposits.
Most of the money currently in circulation is in the form of bank deposits, which include current and savings accounts. Although such deposits are created by commercial banks, central banks may influence them via monetary policy.
Lastly, banks have access to a special form of money called “bank reserves”, i.e. their deposits with central banks (or, in the case of the euro area, with the Eurosystem), which, together with the banknotes and coins in circulation, make up the “monetary base”.
In the euro area, money is denominated in euro
.