Courts at both the federal and state level serve to interpret laws, clarify legal precedents, and ensure due process. There are typically four levels of courts - district/trial courts, appellate courts, supreme courts, and specialized courts. Federal courts hear cases involving federal law or where parties are from different U.S. states, while state court systems are organized differently in each state but generally have limited jurisdiction courts, courts of general jurisdiction, intermediate appellate courts, and a state supreme court. Key participants in the legal system include judges, prosecutors, and defense attorneys.