There are currently three levels in the federal court system, the district courts, court of appeals, and the Supreme Court of the United States. At the highest level the provisions of the Supreme Court are:
1- original jurisdiction- those cases against ambassadors or disputes between two or more states
2- appellate jurisdiction- cases dealing with federal law from lower courts or those from the individual state Supreme Courts. For example, something sought as unconstitutional or that an act of Congress that has been denied.
The federal courts are the branch of government that has the least said about it in the Constitution. For example, the Constitution does not say that the courts have the power to say what laws are and are not constitutional (but the courts have this power today).
Here are a few things the Constitution does say:
- There will be a Supreme Court and some (not specified) lower courts.
- Judges will be appointed by the president with advice and consent of the Senate and will stay in office in "good behavior" -- meaning as long as they're not impeached and convicted.
- The courts will have jurisdiction over any case where the US is suing or being sued
- And any case where a state is suing another state
- And cases between citizens of different states
For other cases where the federal courts have jurisdiction, follow the link.