United States bankruptcy court in the context of "U.S. federal judicial districts"

Subject-matter jurisdiction, also called jurisdiction ratione materiae, is a legal doctrine regarding the ability of a court to lawfully hear and adjudicate a case. Subject-matter relates to the nature of a case; whether it is criminal, civil, whether it is a state issue or a federal issue, and other substantive features of the case. Courts must have subject-matter jurisdiction over the particular case in order to hear it. A court is given the ability to hear a case by a foundational document, usually a Constitution. Courts are granted either general jurisdiction or limited jurisdiction, depending on their type. For example, in the US, state courts have general jurisdiction over the affairs within their state. That means, for most cases, subject-matter jurisdiction of the state courts covers nearly all subjects within that state, such as family law, state criminal law, state civil claims, state tort claims, etc. That power is usually vested in the state courts by their state Constitution. Limited jurisdiction, by contrast, would mean a court does not have jurisdiction over any given case unless specific conditions are met. US federal courts are courts of limited jurisdiction, as specific conditions, as outlined in 28 USC 1332, must be met before a federal court can hear a case.

Subject-matter jurisdiction must be distinguished from personal jurisdiction, which is the power of a court to render a judgment against a particular defendant, and territorial jurisdiction, which is the power of the court to render a judgment concerning events that have occurred within a well-defined territory. Unlike personal or territorial jurisdiction, lack of subject-matter jurisdiction cannot be waived. A judgment from a court that did not have subject-matter jurisdiction is forever a nullity. To decide a case, a court must have a combination of subject (subjectam) and either personal (personam) or territorial (locum) jurisdiction.

A court of equity, also known as an equity court or chancery court, is a court authorized to apply principles of equity rather than principles of law to cases brought before it. These courts originated from petitions to the Lord Chancellor of England and primarily heard claims for relief other than damages, such as specific performance and extraordinary writs. Over time, most equity courts merged with courts of law, and the adoption of various Acts granted courts combined jurisdiction to administer common law and equity concurrently. Courts of equity are now recognized for complementing the common law by addressing its shortcomings and promoting justice.

In the early years of the United States, some states followed the English tradition of maintaining separate courts for law and equity. Others combined both types of jurisdiction in their courts, as the US Congress did for federal courts. United States bankruptcy courts serve as an example of a US federal court that operates as a court of equity. A few common law jurisdictions, such as the U.S. states of Delaware, Mississippi, New Jersey, South Carolina, and Tennessee, continue to preserve the distinctions between law and equity as well as between courts of law and courts of equity. In New Jersey, this distinction is upheld between the civil and general equity divisions of the New Jersey Superior Court.