A judge, or arbiter of justice, is a lead official who presides over a court of law, either alone or as part of a panel of judges. The powers, functions, method of appointment, discipline, and training of judges vary widely across different jurisdictions. The judge is like an umpire in a game and conducts the trial impartially and in an open court. The judge hears all the witnesses and any other evidence presented by the parties of the case and then issues a ruling on the matter at hand. In some jurisdictions, the judge’s powers may be shared with a jury.