According to Wikipedia: "The Chief Justice of the United States is the head of the United States federal court system and the chief judge of the Supreme Court of the United States. He is one of nine Supreme Court justices; the other eight are the Associate Justices of the Supreme Court of the United States.
The Chief Justice is the highest judicial officer in the country. He acts as a chief administrative officer for the federal courts and appoints the director of the Administrative Office of the United States Courts. He also serves as a spokesman for the judicial branch...
The Chief Justice leads the business of the Supreme Court. In the case of an impeachment trial of a President, which has occurred twice in American history, the Chief Justice presides over the Senate. In modern tradition, the Chief Justice also has the duty of administering the oath of office of the President of the United States, but this is not required by the Constitution or any other law.
The first Chief Justice was John Jay. The current chief justice is John G. Roberts, Jr., who was nominated by President George W. Bush and took office on September 29, 2005 upon his confirmation by the Senate on a vote of 78-22 for confirmation. The salary of the Chief Justice is set by Congress, and it is slightly higher than that of the Associate Justices. As of 2008[update], it is $217,400 per year."