A court-martial or court martial is a military court or a trial conducted in such a court. A court-martial is empowered to determine the guilt of members of the armed forces subject to military law, and, if the defendant is found guilty, to decide upon punishment. In addition, courts-martial may be used to try prisoners of war for war crimes. The Geneva Conventions require that POWs who are on trial for war crimes be subject to the same procedures as would be the holding military's own forces. Finally, courts-martial can be convened for other purposes, such as dealing with violations of martial law, and can involve civilian defendants.

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.