Some states do not want to be part of the EU. Other states are not allowed to be part of the EU. If a state wants to join the EU it has to fulfil many requirements. For example, the state has to be a democracy. That means: the people vote for their own parliament and government. Another example is that the courts in the state must be independent. Another requirement is that the country must take on the laws of the EU.
When a country wants to join the EU, there are many negotiations. In the end the EU states vote. All states must agree for a country to be admitted to the EU.
Translation: Cai Nebe.