How the European Union Works

How the European Union Functions

French President Emmanuel Macron talks to the media at the end of an EU chief of state summit in the Europa, the EU Council headquarters on Oct. 18, 2018, in Brussels, Belgium. Thierry Monasse/Getty Images

The 28 nations that belong to the EU work together by participating in a number of common institutions, which set policy and promote their common interests. Here are some of the major ones [source: Archick]:

The European Council develops the strategies that guide EU policies, and is composed of the heads of state of the member countries, in addition to the president of the European Commission (whose function we'll explain in a minute). The council also has its own president, who is appointed by the member countries.
The European Commission in some ways is like the executive branch of the U.S. government, in that carries out the policies developed by the European Council. It's composed of one commissioner from each EU nation. One serves as commission president, while the others handle various portfolios, from agriculture to trade policy.
The Council of the European Union, aka the Council of Ministers, represents the national governments of EU members. The council might bring together all of the nations' agriculture ministers to discuss farm policy, for example, or convene foreign ministers to talk about how to deal with the Middle East. The council enacts legislation, usually based upon proposals offered by the commission and approved by the European Parliament.
The European Parliament represents the ordinary citizens of EU countries. It has 751 members who are elected to five-year terms, and countries are represented in proportion to population size. Unlike, say, U.S. Congress, the EU parliament can't write or enact legislation by itself, but in conjunction with the council, it helps decide how the EU's budget is spent.
The Court of Justice interprets EU laws and issues binding rulings.
The European Central Bank controls the euro and manages the union's monetary policy.

Decisions taken by the EU regarding economic and social policies are legally binding on all member nations, as long as the majority votes for them. However, for issues relating to security, agreement must be unanimous. One government can veto a decision and end it. For issues relating to justice policy, unanimity was also required, but in 2009, the Treaty of Lisbon changed that to a majority agreement.