The federal court system has three components with three different levels of power: The U.S. Supreme Court, the U.S. District Court, and the U.S. Circuit Court of Appeals. Article III of the Constitution created The Supreme Court, which is the highest court in the system, and Article III also created a system of lower courts, which includes 13 U.S. circuit courts of appeals (or appellate courts) and 94 U.S. district courts (or trial courts).
U.S. district courts exist in every state and contain panels of two to eight judges. Each case is tried by a judge and decided on by a jury. These district courts, or trial courts, rule in civil suits that involve a violation of a person’s constitutional rights or a violation of U.S. laws. They also rule in civil or criminal cases in which the United States is a party in the lawsuit. The U.S. district courts have no power to hear appeals from lower courts. Appeals are handled by the U.S. circuit courts of appeals, or appellate courts.
These 13 U.S. circuit courts of appeals rule in both civil and criminal cases in which one or both parties are contesting the judgment in a U.S. district court. The job of the appellate courts is to determine whether the law was correctly applied in the original judgment. Thus, they have a lot of power in the U.S. court system and often set legal precedents. Each case tried in an appellate court is heard by three judges.