Article Three of the United States Constitution establishes the judicial branch of the U.S. federal government. Under Article Three, the judicial branch consists of the Supreme Court of the United States, as well as lower courts created by Congress. Article Three empowers the courts to handle cases or controversies arising under federal law, as well as other enumerated areas. Article Three also defines treason.
Section 1 of Article Three vests the judicial power of the United States in "one supreme Court", as well as "inferior courts" established by Congress. Section 1 authorizes the creation of inferior courts, but does not require it; the first inferior federal courts were established shortly after the ratification of the Constitution with the Judiciary Act of 1789. Section 1 also establishes that federal judges do not face term limits, and that an individual judge's salary may not be decreased. Article Three does not set the size of the Supreme Court or establish specific positions on the court, but Article One establishes the position of chief justice. Along with the Vesting Clauses of Article One and Article Two, Article Three's Vesting Clause establishes the separation of powers among the three branches of government.