Federal Courts & What They Do

You probably realize that there are both federal courts and state courts. The two kinds of courts are a result of a principle of our Constitution called federalism. Federalism gives some functions to the United States government and leaves the other functions to the states. The functions of the U.S.-or federal-government involve the nation as a whole and include regulating commerce between the states and with foreign countries, providing for the national defense, and administering federal lands and other property. State governments perform most of the functions you probably associate with "government," such as running the schools, managing the police departments, and paving the streets.
Federal courts are established by the U.S. government to decide disputes concerning the federal Constitution and laws passed by Congress, called statutes. State courts are established by a state, or by a county or city within the state. Although state courts must enforce the federal Constitution and laws, most of the cases they decide involve the constitution and laws of the particular state.