Judge
A judge is a public official with authority to decide cases — to preside over proceedings, apply the law to facts, and issue binding rulings and judgments. Federal judges under Article III are nominated by the President and confirmed by the Senate, and they "hold their Offices during good Behaviour" — effectively life tenure — with salaries that cannot be reduced. They serve on the Supreme Court, the courts of appeals, and the district courts; other judicial officers (magistrate judges, bankruptcy judges, administrative law judges) exercise judicial-type authority on a different statutory footing.
A judge is a public official with authority to decide cases — to preside over proceedings, apply the law to facts, and issue binding rulings and judgments. Federal judges under Article III are nominated by the President and confirmed by the Senate, and they “hold their Offices during good Behaviour” — effectively life tenure — with salaries that cannot be reduced. They serve on the Supreme Court, the courts of appeals, and the district courts; other judicial officers (magistrate judges, bankruptcy judges, administrative law judges) exercise judicial-type authority on a different statutory footing.
Example: Article III, Section 1 of the Constitution provides that the judicial power is vested in one supreme Court and such inferior courts as Congress establishes, and that “the Judges, both of the supreme and inferior Courts, shall hold their Offices during good Behaviour, and shall, at stated Times, receive for their Services, a Compensation, which shall not be diminished during their Continuance in Office.”
Common misconception: “During good Behaviour” is not the same as serving at will. A federal judge keeps the office for life unless removed by impeachment (conviction by the Senate) — the salary-protection and tenure provisions exist precisely to shield judges from pressure by the other branches.