The European Union (EU) is a family of democratic European countries, committed to working together for peace and prosperity.
It is not a State intended to replace existing states, but it does represent a greater compromise of sovereignty than any other international organization.
The EU is unique; its Member States have set up common institutions to which they delegate some of their sovereignty so that decisions on specific matters of joint interest can be made democratically at European level.
This pooling of sovereignty is also called "European integration"