The EU operates through a hybrid system of supranational independent institutions and intergovernmentally made decisions negotiated by the member states. Important institutions of the EU include the European Commission, the Council of the European Union, the European Council, the Court of Justice of the European Union, and the European Central Bank. The European Parliament is elected every five years by EU citizens.
The EU has developed a single market through a standardised system of laws which apply in all member states. Within the Schengen Area (which includes EU and non-EU states) passport controls have been abolished. EU policies aim to ensure the free movement of people, goods, services, and capital, enacts legislation in justice and home affairs, and maintains common policies on trade, agriculture, fisheries and regional development. A monetary union, the eurozone, was established in 1999 and is currently composed of 17 member states. Through the Common Foreign and Security Policy the EU has developed a limited role in external relations and defence. Permanent diplomatic missions have been established around the world and the EU is represented at the United Nations, the WTO, the G8 and the G-20.
With a combined population of over 500 million inhabitants, the EU generated a nominal GDP of 16,242 trillion U.S. dollars in 2010 which represents an estimated 20% of global GDP when measured in terms of purchasing power parity).