The Court of Justice of the European Union (CJEU) is the supreme court in the European Union (EU) and it makes sure that the law is observed in the interpretation and application of the Treaties of the European Union.
There exists a set of procedural rules specifically aimed at the CJEU, which regulates a wide variety of responsibilities and procedures. National Courts have the possibility to refer questions concerning the interpretation of the European Union law to the CJEU, on the occasion that there exists an initial case. Based on the CJEU’s ruling, the national court can make a decision on said initial case.