The traditional division of the various functions of government is: legislative, executive, and judicial. In the U.S., each area is fulfilled by separate institutions to “check” potential abuses and balance each of the branches. Similarly in the EU there are three main political institutions that constitute the EU’s executive and legislative branches, as well as an independent judiciary with the power to exercise judicial review.
The Court of Justice of the European Union is the highest court in the EU in matters of EU law. Its independent judgements can affect both member states and individuals. It is the intermediary between member states, institutions and individuals in disputes over EU law.
The President of the European Commission is one of the most powerful officeholders in the EU, controlling the European Commission (executive arm of the EU) which collectively has a monopoly on initiating all EU legislation and is responsible for ensuring its enforcement. The President is responsible for allocating portfolios to members of the Commission and can reshuffle or dismiss them if needed. She determines the Commission’s policy agenda and all the legislative proposals it produces; in practice, no policy can be proposed without the President’s agreement.
The European Parliament is the only directly-elected body, representing more than 450 million citizens. It is, in many instances, comparable to the Congress of the United States, itself elected directly by the American people to legislate on a federal level.