Appeal: to take a case to a higher court for another review; in general, when a party loses a case, it has the right to appeal once to an appellate court. If the party loses the case in an appellate court, it can only take its appeal to yet a higher court if that higher court accepts to hear the case.

Amicus Curiae: a friend of the court; a person, who is not a member of a case's litigation team, invited by the court to give his/her views on that case.

Brief: a written document arguing in favor of one side over another.

Case: an action or suit brought to court.

Civil Law: the body of law that concerns the private rights of individuals; different from the body of law concerning criminal cases.

Circuit Court: one of twelve regional federal courts of appeals.

Class Action: a lawsuit brought by one person or group of people representing all persons sharing a common situation.

Concurring Opinion: a decision of a justice or a judge in support of the court's majority opinion, but offering an alternate rationale for reaching that decision.

Court of Appeals: one of twelve circuit courts that hears cases being appealed from a lower court.

Criminal Law: body of law dealing with punishing those who have committed crimes, or broken laws.

Defendant: in a civil case, the party being charged, or brought to court, by the plaintiff; in a criminal case, the party being accused of the crime.

Dissenting Opinion: an opinion of a justice or judge that disagrees with the decision reached by the majority of the court.

District Court: trial courts of the federal system; there are 94 U.S. judicial districts.

Due Process: fair and regular legal procedures; no individuals can be denied the right to life, liberty, and property without the due process of law (under the Fifth and Fourteenth Amendments).

Judicial Review: the Supreme Court reserves the right to review and take action against any legislation (made by elected officials) it deems to be unconstitutional.

Jurisdiction: a court's authority to hear a case.

Majority Opinion: the decision issued on a case by the court; it represents the opinion of the majority of the justices or judges.

Opinion: the decision, or ruling, of the court in a particular case; it invokes the laws in question as well as the reasoning behind the final decision of the court.

Original Jurisdiction: defines the types of cases that can go directly to a certain type of court; for example, the Supreme Court has original jurisdiction (as defined under Article III, Section 2 of the Constitution) in cases in which a state is a party; therefore, disputes involving a state can go directly to the Supreme Court without first going to a lower court (Further, the Supreme Court has original and exclusive jurisdiction over disputes between states, so in such cases the Supreme Court is the only court allowed to hear the case.)

Overturn: to reverse the opinion reached in a lower court; occurs in a court of appeals.

Petitioner: the party (the plaintiff or the appellant) who petitions a court to take action; in an appellate case the petitioner can be either the plaintiff or the defendant.

Plaintiff: the party bringing a charge or a suit against another party.

Precedent: a ruling from one case that is used in deciding similar cases.

Respondent: the party against whom the petitioner files; in an appellate case the respondent may be the plaintiff or the defendant from the lower court.

Rule of Four: a case being appealed can only be argued in the Supreme Court if four of the nine justices must agree.

Separation of Powers: the division of power amongst the three branches of government; the legislative branch makes laws; the executive branch carries out laws; the judicial branch decides the outcome of disputes under the law.

Stare Decisis: the doctrine, or principal, by which a case decided by the court acts as a precedent and, thus, influences the ruling on similar cases.

Subpoena: an order to come before a jury, a court, or a legislative hearing.

Writ of Certiorari: the Supreme Court's decision to hear a case from a lower court; Formally, the Supreme Court will issue a writ of certiorari which will serve as an order a lower court to send a specific case's record to the Court for its review.