Activism (judicial). The willingness of a judge to inject into a case his or her own personal values about what is good and bad public policy. See also self-restraint (judicial).

Actus reus. The material element of the crime, which may be the commission of a forbidden action (for example, robbery) or the failure to perform a required action (for example, to stop and render aid to a motor vehicle accident victim).

Adversarial process. The process used in American courtrooms where the trial is seen as a battle between two opposing sides, and the role of the judge is to act as a sort of passive referee. See also inquisitorial method.

Advisory opinions. Rendering a decision on an abstract or hypothetical question (something that American courts are not supposed to do).

Alternative dispute resolution (ADR). Methods of resolving disputes (often with the help of neutral third parties) without a trial. Mediation and arbitration are two well-known ADR techniques.

Amicus curiae. ("Friend of the court.") A person (or group), not a party to a case, who submits views (usually in the form of written briefs) about how the case should be decided.

Answer. The formal written statement by a defendant responding to a civil complaint and setting forth the grounds for his or her defense.

Appellate jurisdiction. The authority of a higher court to review the decision of a lower court.

Arraignment. The process in which the defendant is brought before the judge in the court where he or she is to be tried to respond to the grand jury indictment or the prosecutor's bill of information.

Bail. A sum of money put up with the court by the defendant to ensure that he or she will appear at the time of trial.

Bench trial. Trial without a jury in which the judge decides which party prevails.

Bill of attainder. A law, forbidden by the U.S. Constitution, that makes conduct illegal for one person (or class of persons) but not for the population in general.

Bill of information. A statement of the charges against the accused prepared by the prosecutor, which, if approved by a judge, will require the accused to stand trial for the alleged crimes. This is used in states that do not employ a grand jury.

Certification. The procedure by which one of the U.S. appeals courts asks the U.S. Supreme Court for instructions or clarification about a particular legal matter. Either the justices may choose to honor this request or not, or they may request that the entire record of the case be sent to the Supreme Court for review and final judgment.

Civil law. The law that pertains to the relationship between one private citizen and another, and between a private citizen and a corporation, or between one corporation and another.

Class action. A suit brought by persons having similar grievances against a common entity; for example, a group of smokers with lung cancer suing a tobacco company.

Collegial courts. Courts having more than one judge, which are almost always appellate courts.

Common law. A system of law inherited from England based on legal precedents or tradition instead of statutory law or systematic legal codes.

Complaint. A written statement filed by the plaintiff that initiates a civil case. It states the wrongs allegedly committed by the defendant and requests relief from the court.

Concurrent jurisdiction. A situation in which two courts have a legal right to hear the same case. For example, both the U.S. Supreme Court and U.S. trial courts have concurrent jurisdiction in certain cases brought by or against ambassadors or counsels.

Concurring opinion. An opinion by a member of a court that agrees with the result reached in a case but offers its own rationale for the decision.

Corpus juris. The entire body of law for a particular legal entity.

Courtroom workgroup. The regular participants in the day-to-day activities of a particular courtroom. The most visible members of this group are judges, prosecutors, and defense attorneys.

Court of appeals. A court that is higher than an ordinary trial court and has the function of reviewing or correcting the decisions of trial judges.

Crime. An offense against the state punishable by fine, imprisonment, or death.

Criminal law. The law that pertains to offenses against the state itself, actions that may be directed against a person but that are deemed to be offensive to society as a whole -- for example, armed robbery or rape.

Cross-examination. During a trial, the questions posed to a witness who has been called to the stand by the opposing attorney.

Damages. Money paid by defendants to successful plaintiffs in civil cases to compensate the plaintiffs for their injuries. Compensatory damages are designed to cover the plaintiff's actual loss; punitive damages are designed to punish the defendant.

Declaratory judgment. When a court outlines the rights of the parties under a statute, a will, or a contract.

Defendant. In a civil case, the person or organization against whom the plaintiff brings suit; in a criminal case, the person accused of the crime.

Deposition. An oral statement made before an officer authorized by law to administer oaths. Such statements are often taken to examine potential witnesses in the discovery process.

Discovery. The process by which lawyers learn about their opponent's case in preparation for trial. Typical tools of discovery include depositions, interrogatories, and requests for documents.

Dissenting opinion. An opinion by a member of a court that disagrees with the result reached in the case by the court.

Diversity of citizenship suit. A civil legal proceeding brought by a citizen of one state against a citizen of another state.

En banc. ("In the bench" or "as a full bench.") Court sessions with the entire membership of a court participating, not just a smaller panel of judges.

Equity. That realm of the law in which the judge is able to issue a remedy that will either prevent or cure the wrong that is about to happen; for example, an injunction against an illegal strike by a union.

Ex post facto law. Forbidden by the U.S. Constitution, this law declares conduct to be illegal after the conduct takes place.

Federal question. If a court case centers around the interpretation of a federal law, the U.S. Constitution, or a treaty, then it contains a federal question and the case may be heard by a U.S. court.

Felony. Any offense for which the penalty may be death or imprisonment in a penitentiary.

Grand jury. A body of 16 to 23 citizens who listen to evidence of criminal allegations, which is presented by the prosecutors, and determine whether probable cause exists to believe an individual committed an offense. See also indictment.

Habeas corpus. A writ (court order) that is usually used to bring a prisoner before the court to determine the legality of his or her imprisonment.

Impeachment. The only way in which a federal judge may be removed from office. The House of Representatives brings the charge(s), and the Senate, following trial, convicts by a two-thirds vote of the membership.

Indictment. The decision of a grand jury to order a defendant to stand trial because the jury believes that probable cause exists to warrant a trial.

Inquisitorial method. The procedure used in most European and Latin American courtrooms in which the judge and jury take an active role in the trial and the attorneys act only to aid and supplement the judicial inquiry. See also adversarial process.

Interrogatories. Written questions sent by one party in a lawsuit to an opposing party as part of pretrial discovery in civil cases. The party receiving the interrogatories is required to answer them in writing under oath.

Judgment. The official decision of a court finally resolving the dispute between the parties to the lawsuit.

Judicial review. The power of the judicial branch to declare acts of the executive and legislative branches unconstitutional.

Jurisdiction. The authority of a court to hear and decide legal disputes and to enforce its rulings.

Justiciability. Whether a judge ought to hear or refrain from hearing certain types of cases. It differs from jurisdiction, which pertains to the technical right of a judge to hear a case. For example, lawsuits dealing with political questions are considered nonjusticiable.

Law. A social norm that is sanctioned in threat or in fact by the application of physical force. The party that exercises such physical force is recognized by society as legitimately having this kind of authority, such as a police officer.

Magistrate. A lower level judicial official to whom the accused is brought after the arrest. A magistrate has the obligation of informing the accused of the charges against him or her and of his or her legal rights.

Mandatory sentencing laws. Statutes that require automatic jail time for a convicted criminal, usually for a minimum period of time. These laws are often for violent crimes in which a gun was used and for habitual offenders.

Mens rea. The mental element of the crime -- that is, what was intended by the perpetrator of the crime. Usually the more intentional and willful the mental state, the more serious the crime.

Merit selection. A method of selecting state judges that requires the governor to make the appointment from a short list of names submitted by a special commission established for that purpose. After serving for a short period of time, the judge must run in a retention election. Voters thus determine whether the judge should be retained for a full term.

Misdemeanor. A petty crime. Punishment usually is confinement in a city or county jail for less than a year.

Moot. Describes a case when the basic facts or the status of the parties have significantly changed in the interim between when the suit was filed and when it comes before the judge.

Nolo contendere. ("No contest.") A plea by a criminal defendant in which he or she does not deny the facts of the case but claims that he or she has not committed any crime, or it may mean that the defendant does not understand the charges.

Opinion of the court. A judge's written explanation of the court's decision. Because the case may be heard by a panel of judges in an appellate court, the opinion can take two forms. If all the judges completely agree with the result, one judge will write the opinion for all. If all the judges do not agree, the formal decision will be based on the view of the majority, and one member of the majority will write the decision.

Oral argument. An opportunity for lawyers to summarize their position before the court and to answer the judges' questions.

Ordinance-making power. The power of state governors to fill in the details of legislation passed by state legislatures.

Original jurisdiction. The court that by law must be the first to hear a particular type of case. For example, in suits with at least $75,000 at stake between citizens from different states, the federal district courts are the courts of original jurisdiction.

Overcharging. The process whereby a prosecutor charges a criminal defendant with crimes more serious than the facts warrant to obtain a more favorable plea bargain from the defendant's attorney.

Per curiam. ("By the court.") An unsigned opinion of the court, often brief.

Peremptory challenge. An objection that an attorney might have to a prospective juror. The juror may be eliminated from the array without the attorney having to give a public reason for the objection. The number of such challenges is limited by law.

Petit jury (or trial jury). A group of citizens who hear the evidence presented by both sides at trial and determine the facts in dispute.

Plaintiff. The person who files the complaint in a civil lawsuit.

Plea bargain. A bargain or deal that has been struck between the prosecutor and the defendant's attorney whereby some form of leniency is promised in exchange for a guilty plea.

Political question. When the courts refuse to rule because they believe that under the U.S. Constitution the founders meant that the matter at hand should be dealt with by Congress or the president, the courts are refusing to rule on a political question.

Private law. This deals with the rights and obligations that private individuals and institutions have when they relate to one another.

Probation. Punishment for a crime that allows the offender to remain in the community and out of jail so long as he or she follows court-ordered guidelines about his or her behavior.

Pro bono publico. ("For the public good.") Usually refers to legal representation undertaken without fee for some charitable or public purpose.

Public law. The relationships that individuals have with the state as a sovereign entity -- for example, the tax code, criminal laws, and Social Security legislation.

Recess appointment. An appointment made by the president when Congress is in recess. Persons appointed in this manner may hold office only until Congress reconvenes.

Reversible error. An error committed at the trial court level that is so serious that it requires the appellate court to reverse the decision of the trial judge.

Rule of four. On the Supreme Court at least four justices must agree to take a case before the Court as a whole will consider it.

Rule of 80. When the sum of a federal judge's age and number of years on the bench is 80, Congress permits the individual to retire with full pay and benefits.

Self-restraint (judicial). The reluctance of a judge to inject into a case his or her own personal ideas of what is good or bad public policy. See also activism (judicial).

Senatorial courtesy. Under this practice senators of the president's political party who object to a candidate that the president wishes to appoint to a district judgeship in their home state have a virtual veto over the nomination.

Sequestration (of jury). In very important or notorious cases the jury may be kept away from the public eye by the judge, and this usually means that the jury is housed and fed as a group at taxpayers' expense.

Socialization (judicial). The process by which a new judge is formally and informally trained to perform the specific tasks of the judgeship.

Standing. The status of someone who wishes to bring a lawsuit. To have standing the person must have suffered (or be immediately about to suffer) a direct and significant injury.

Stare decisis, the doctrine of. ("Stand by what has been decided.") In effect, the tradition of honoring and following previous decisions of the courts and established points of law.

Statutory law. The type of law enacted by a legislative body, such as Congress, a state legislature, or a city council.

Three-judge panels (of appellate courts). Most decisions of the U.S. courts of appeals are not made by the entire court sitting together but by three judges, often selected at random, to hear any given case.

Three-judge district courts. With some types of important cases Congress has mandated that the case cannot be heard by a U.S. trial judge acting alone but has to be decided by a panel of three judges, one of whom must be an appeals court judge.

Tort. A civil wrong or breach of duty to another person.

Trial de novo. A new trial in which the entire case is retried as if no prior trial had occurred.

Venue. The geographical location in which a case is tried.

Voir dire. The procedure by which opposing attorneys question potential jurors to determine whether the jurors might be prejudicial to their individual cases.

Warrant. Issued after a complaint, filed by one person against another, has been presented and reviewed by a magistrate who has found probable cause for the arrest.

Writ of certiorari. An order issued by the U.S. Supreme Court directing the lower court to transfer records for a case that it will hear on appeal.