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 km (1,634,469 sq mi) and an estimated population of more than 450 million as of 2025. The EU is often described as a sui generis political entity combining characteristics of both a federation and a confederation.
Containing 5.5% of the world population in 2023, EU member states generated a nominal gross domestic product (GDP) of around âŹ17.935 trillion in 2024, accounting for approximately one sixth of global economic output. Its cornerstone, the Customs Union, paved the way to establishing an internal single market based on standardised legal framework and legislation that applies in all member states in those matters, and only those matters, where the states have agreed to act as one. EU policies aim to ensure the free movement of people, goods, services and capital within the internal market; enact legislation in justice and home affairs; and maintain common policies on trade, agriculture, fisheries, and regional development.