According to studies, the Article III of the Constitution invests the judicial power of the United States and the federal court system. This article creates the U.S. Supreme Court and gives congress the authority to create the lower federal courts. When parties become dissatisfied with a decision of a U.S. district court, S.S Court of Claims, etc, they may appeal to the U.S. Court of appeals. The United States Supreme Court is the final attributer. The federal court hears cases that deal with the constitutionality of a law. They hear cases involving the laws and treaties of the United States. They also hear cases involving ambassadors and public ministers, disputes between two or more states, admiralty law, bankruptcy and habeas corpus issues.
The Constitutional and laws of each state are what establish and make up the state courts. The Supreme Court is the highest court of the state. Some state court also has intermediate court of appeals. The intermediate court is where someone goes when they are not satisfied with the courts decision. Below the appeals courts are the circuit court and the district courts. Normally states have courts that handle certain legal matters. Some are probate courts, juvenile and family courts. State courts also handle most criminal cases, tort cases, and contract cases.