The European Union is perhaps the world's biggest single market.
The Union brings together nearly 500 million citizens and four of the world's seven largest economies. It now has a common currency for 16 of its member states, covering 320 million citizens.
In this "borderless" Europe, people and products can move freely from one place to another. This means that, as a citizen, you can travel to any EU country without a visa and many without a passport. It also means that people and businesses can buy and sell goods wherever they want without having to pay special customs duties or taxes.