Jurisdiction law is made up of the law that applies in determining whether a court has the authority to hear a given legal case or not. For a court to have jurisdiction over a matter within the United States, both personal and subject matter jurisdiction are required. This means the court must have a vested interest in deciding the matter at hand and must have provided sufficient benefits to the people involved that it is fair to subject the people to the court's authority.
Personal jurisdiction exists because it is not fair for a court to have authority over someone whom has received no benefit from the law enforcement system or court within that community. Under jurisdiction law, personal jurisdiction is vested in the court as soon as the person enjoys some benefits from the state or federal government that the court is under. For example, all individuals living within the United States are subject to personal jurisdiction by the federal court, because those individuals enjoy living in the United States. A person may also be subject to the jurisdiction of the state court if he has sufficient contact with the state: for example, if he drives in the state and he then gets into a car accident, the state can have jurisdiction over the car accident claim because the person drove on its roads.
Under jurisdiction law, subject matter jurisdiction exists when a court has an interest in the issue being decided. For example, a state court has exclusive jurisdiction when people are having an issue determining who owns a given piece of property, because the state's interest in deciding how land disputes are settled is very important. In contrast, federal court has subject matter jurisdiction over cases where someone questions the constitutionality of a law. It also has jurisdiction over cases in which a federal law — such as the Equal Opportunity Employment Act — has been broken or a federal law is invoked, because the federal government has the greatest interest in determining how federal laws are interpreted.
Jurisdiction law is also designed to minimize forum shopping. Forum shopping occurs when there are two courts with concurrent jurisdiction that could each decide a case. The plaintiff and defendant thus have the opportunity to decide which court system it believes will treat their particular case more favorable. Jurisdiction law aims to minimize this by limiting which cases can be transferred to a different court system.