The euro is the most significant achievement of European monetary reform since the Roman Empire. The euro not only makes the European single market more perfect, but also facilitates the free trade among the countries in the euro zone, which is an important part of the EU integration process.

Although Monaco, San Marino and Vatican are not EU countries, they used to use French francs or Italian lira as their currencies, and they also used euros, and authorized to mint a small number of their own euro coins. Some non-EU countries and regions, such as Montenegro, Kosovo and Andorra, also use the euro as a payment tool.

The euro is managed by european system of central banks, which is composed of the European Central Bank and the central banks of the euro zone countries. The European Central Bank, headquartered in Frankfurt, Germany, has the power to independently formulate monetary policy. The central banks of euro zone countries participate in the printing, casting and distribution of euro banknotes and coins, and are responsible for the operation of the euro zone payment system.