The European Union is a unique political and economic partnership between 27 democratic European countries aiming at peace, prosperity and freedom for its 500 million citizens, in a fairer and safer world.
It is a constantly evolving structure which has no historical precedent. The primary legislation of the EU are the treaties signed between member states. These treaties lay down the basic policies of the EU, establish its institutional structure, legislative procedure and powers. Some of the main treaties are: the EEC Treaty of Rome (1957), the Single European Act (1986), the Treaty of Maastricht (1992), the Amsterdam Treaty (1997) and the Lisbon Treaty (2007).
The EU's main institutions are: the European Parliament, the European Council, the Council of the European Union, and the European Commission.
The European Parliament (EP) is elected every five years by the people of the European Union to represent their interests. The main job of the EP is to pass European laws on the basis of proposals presented by the European Commission. The EP shares this responsibility with the Council of the European Union. The Parliament and the Council also share joint authority for approving the EU’s annual budget. The main meetings of the Parliament are held in Strasbourg (France), others in Brussels (Belgium).
(http://www.europarl.europa.eu/)
It consists of the Heads of State or Government of the Member States, together with its President and the President of the Commission. The High Representative of the Union for Foreign Affairs and Security Policy takes part in its work. The European Council defines the general political direction and priorities of the European Union. It does not exercise legislative functions. The European Council meets twice every six months, convened by its President. When the situation so requires, the President will convene a special meeting. The President's term of office is two and a half years, renewable once. The European Council usually meets in Brussels.
http://www.european-council.europa.eu/
It is the EU’s principal decision-making body. It shares with the European Parliament the responsibility for passing EU laws. The Council of the EU consists of ministers from the national governments of all the EU countries. Meetings are attended by whichever ministers are responsible for the items to be discussed. Every six months, a different member state assumes the so-called Presidency of the EU, meaning that it chairs these meetings and sets the overall political agenda. The rotating presidency does not apply to the Foreign Affairs Council, which is chaired by the EU's High Representative for Foreign Affairs and Security Policy.
http://www.consilium.europa.eu/
It is the EU’s executive body and represents the interests of the EU as a whole. It drafts proposals for new European laws, which it presents to the European Parliament and the Council. It puts into practice the EU's common policies and manages the EU's funds and programmes. The Commission also plays its role as "guardian of the treaties" making sure that everyone abides by the EU treaties and laws. It can act against rule-breakers, taking them to the European Court of Justice if necessary.
The Commission consists of 27 Commissioners — one from each EU country. The president of the Commission is chosen by the 27 EU governments and endorsed by the European Parliament. The other commissioners are nominated by their national governments in consultation with the incoming president, and must be approved by the European Parliament. They do not represent the governments of their home countries. Instead, each of them has responsibility for a particular EU policy area. They are all appointed for a period of five years.