Each state’s constitution and laws establish the state’s courts, which interpret state laws (and generally not federal laws). A court of last resort, often known as a supreme court, is usually the highest court in the state. Some states also have an intermediate court of appeals. Below these intermediate courts of appeal are the state trial courts, where most lawsuits begin. State trial courts are referred to differently in different states—often as district courts, circuit courts, or superior courts.

State courts are often courts of general jurisdiction—meaning they hear all types of cases—involving criminal law, family law, probate law, and general disputes involving money and property. But more populated counties often have courts of specific jurisdiction, such as family courts that only hear family law matters (divorce, child custody, child support); criminal courts that only hear criminal matters; and probate courts that only handle the probate of estates and related litigation.

In New Jersey, the state court system is structured with the New Jersey Supreme Court as the highest court, serving as the court of last resort. Below the Supreme Court is the Superior Court, Appellate Division, which is the intermediate appellate court that reviews decisions from the trial courts. The trial level is primarily composed of the Superior Court, which is a court of general jurisdiction and handles a wide range of cases, including criminal, civil, family, and probate matters. New Jersey does not label its trial courts as district or circuit courts, which are terms more commonly used in other states. In addition to these courts, there are also municipal courts that handle minor criminal offenses, municipal ordinance violations, and traffic cases. New Jersey's court system is designed to ensure that there is a clear hierarchy and process for appeals, with the Supreme Court at the apex, ensuring uniformity and consistency in the application of state law.