A court of cassation is a high-instance court that exists in some judicial systems. Courts of cassation do not re-examine the facts of a case; they only interpret the relevant law. In this, they are appellate courts of the highest instance. In this way, they differ from systems that have a supreme court that can rule on both the facts of a case and the relevant law. The term derives from the Latin cassare, "to reverse or overturn".

A court is any person or institution, often as a government institution, with the authority to adjudicate legal disputes between parties and carry out the administration of justice in civil, criminal, and administrative matters in accordance with the rule of law. In both common law and civil law legal systems, courts are the central means for dispute resolution, and it is generally understood that all people have an ability to bring their claims before a court. Similarly, the rights of those accused of a crime include the right to present a defense before a court.