European Union. The European Union (EU) is a supranational political and economic union of 27 member states that are located primarily in Europe. The Union has a total area of 4,233,255 km2 (1,634,469 sq mi) and an estimated total population of over 449 million. The EU has often been described as a sui generis political entity combining the characteristics of both a federation and a confederation. Containing 5.8% of the world population in 2020, EU member states generated a nominal gross domestic product (GDP) of around US$16.6 trillion in 2022, constituting approximately one sixth of global nominal GDP. Additionally, all EU states except Bulgaria have a very high Human Development Index according to the United Nations Development Programme. Its cornerstone, the Customs Union, paved the way to establishing an internal single market based on standardised legal framework and legislation that...