Euro

The euro is the currency of the European Union. It replaced the currencies previously used by European countries. The Maastricht Treaty, which serves as the EU's constitution, designates the euro as the EU's single currency, and stipulates that the member states' own currencies, with the exception of the United Kingdom[1] and Denmark, are allowed to remain in circulation 'for a while' but must eventually be replaced by the euro. The area where the euro is used is called the eurozone.