Central banks are the most important players in financial markets around the world. By their action, they affect interest rates, the amount of credit and the money supply. All this directly affects overall production and inflation. In this case, we will observe the structure of central banks, especially the European Central Bank and the Croatian National Bank. We will also mention the Federal Reserve System (FED) which is the most important central bank in the world. Central banking in Europe, but also in other parts of the world, comes down to creating and managing a payment currency that is accepted by law. The role of the central bank grows through the conduct of monetary policy, which is an important part of national economic policy. Monetary policy, as part of economic policy, seeks to fulfill its key tasks with its instruments and measures, namely: full employment, price stability, growth of gross domestic product and maintaining balance in the balance of payments. The independence of the central bank is a key precondition for the successful and credible implementation of monetary policy, and thus for the achievement of the central goal of the central bank, which is price stability. Unlike central banks in Europe, the Federal Reserve System is decentralized to 12 banks. Later in the paper, we will explain the operation of the Fed and the difference between the ECB and the FED