Jurisdiction is the right of a governing body to legislate crimes within a geographic boundary and to prosecute individuals who violate those crimes within the geographic boundary. A sovereign nation may only prescribe rules for its own citizens. Thus, the United States cannot create crimes in a foreign jurisdiction.
In the United States, this principal also exists on a state level. In one state a crime may exist, while in another, the same act may not be a crime at all. Similarly, punishments may vary greatly from one state to another.
Jurisdiction also decribes the physical limits of a country's ability to prosecute an individual. If a defendant commits a crime in Country A, and then escapes to Country B, Country A may request Extradition of the individual back to Country A for prosecution.