Jurisdiction concerns the power of the state to affect people, property and circumstances and reflects the basic principles of state sovereignty, equality of states and non-interference in domestic affairs. Jurisdiction is a vital and indeed central feature of state sovereignty, for it is an exercise of authority which may alter or create or terminate legal relationships and obligations. It may be achieved by means of legislative action or by executive action or by judicial action. In each case, the recognised authorities of the state as determined by the legal system of that state perform certain functions permitted them which affect the life around them in various ways. In the UK, Parliament passes binding statutes, the courts make binding decisions and the administrative machinery of government has the power and jurisdiction (or legal authority) to enforce the rules of law. These differences, particularly between the capacity to make law (the prescriptive jurisdiction) and the capacity to ensure compliance with such law (the enforcement jurisdiction), are basic to an understanding of the legal competence of a state. This is to some extent because jurisdiction, although primarily territorial, may be based on other grounds, for example nationality, while enforcement is restricted by territorial factors.

To give an instance, if a man kills somebody in Britain and then manages to reach the Netherlands, the British courts have jurisdiction to try him, but they cannot enforce it by sending officers to the Netherlands to apprehend him.