Original jurisdiction is the exclusive power of the Supreme Court of the United States, where certain matters may be brought directly to the Supreme Court.
In other words, the court has the power to first hear a case in court, contrary to the appellate jurisdiction, which has only the authority to review the jurisdiction of the subordinate court.
Contextually, a case file that can directly bring California to the Supreme Court on Nevada on river pollution is an example of the Supreme Court's original jurisdiction.
