The Supreme Court is the only court mentioned in the Constitution, and is the highest level in the three-tiered Judicial Branch. The Supreme Court hears appeals from the courts of appeals and from the highest level state courts. These appeals generally involve federal law or Constitutional matter. The Supreme Court has complete control over the cases that it chooses to review. Also, Supreme Court justices are appointed by the President, and are appointed for life.
This page offers an introduction to the Supreme Court and Supreme Court research. For more in depth legal research see:
"Article III, §1, of the Constitution provides that '[t]he judicial Power of the United States, shall be vested in one supreme Court, and in such inferior Courts as the Congress may from time to time ordain and establish.'" Image courtesy of Noclip at en.wikipedia [Public domain], via Wikimedia Commons.