It is the 'area' inside of which an oficer of the law or other potentate has legal authority as vested upon him/her by the local government to enforce laws, ordinances, codes etc. In most, but not all, cases this includes the authority to detain and/or arrest (take into custody). The area in which one has authority. An A-ville police officer cannot make an arrest in B-ville for he is out of his jurisdiction. (He can, however, use the authority given to us all as citizens: Citizen's Arrest.)
What is Jurisdiction?
Jurisdiction means the power, right and authority to interpret and apply law.
There are various types of jurisdiction, but the broadest categories are appellate jurisdiction (the right to hear a case on appeal from another court) and original jurisdiction, (the right to hear the case as the original trial court).
Both are related to subject-matter jurisdiction which determines the type of case (subject) a court may hear and personal jurisdiction, the determines the entities whose cases the court may judge, as opposed to territorial jurisdiction, which covers the physical area over which the court has authority.
The US Supreme Court has territorial jurisdiction over the entire United States and its holdings.
Jurisdiction means authority over an area. There are three types of jurisdiction in general-
1. Territorial
2. Pecuniary
3. Act specific.