This chapter discusses the composition, functions and jurisdiction of the European Courts. It discusses indirect actions (preliminary rulings) and direct actions, i.e. actions brought by or against the European Institutions and the Member States, and between the Member States. The Courts are the CJEU, which includes the Court of Justice, the General Court, and specialised courts. The chapter explains the role of the Advocate General (AG), and further discusses rules of procedure, judicial activism, preliminary rulings, the jurisdiction of national courts, discretionary and mandatory references, when national courts should refer, interim measures, effect of preliminary rulings, and the future of preliminary rulings. The chapter also explains the role of the EFTA Court.