Branch of government in which judicial power is vested. The principal work of any judiciary is the adjudication of disputes or controversies. Regulations govern what parties are allowed before a judicial assembly, or court, what evidence will be admitted, what trial procedure will be followed, and what types of judgments may be rendered. Typically present in court are the presiding judge, the parties to the matter (sometimes called litigants), the lawyers representing the parties, and other individuals including witnesses, clerks, bailiffs, and jurors when the proceeding involves a jury. Though the courts' stated function is to administer justice according to rules enacted by the legislative branch, courts also unavoidably make law. In deciding, for example, how legislative provisions are to be applied to specific cases, the courts in effect make law by laying down rules for future cases; this is known as the doctrine of precedent. In some jurisdictions, courts have the power of judicial review, enabling them to declare unconstitutional legislation or acts of the executive.