The European Union is a political and economic union between 27 European countries formed after World War 2 to promote peace. It began with 6 countries signing an agreement in 1951 to share coal and steel resources. The EU aims to protect member states' rights and interests through common economic and political policies across areas like trade, budgets, education and more. It is governed by institutions like the European Council, European Commission, European Parliament, and Court of Justice. The EU also aims to create a single market without trade barriers through policies like adopting a single currency, the euro, which 19 member states currently use.