The political-administrative organization of the Federative Republic of Brazil comprises the Union, the states, the Federal District, and the municipalities. The Union, the states, the Federal District, and the municipalities, are the "spheres of government". The federation is set on five fundamental principles: sovereignty, citizenship, dignity of human beings, the social values of labor and freedom of enterprise, and political pluralism. The classic tripartite branches of government (executive, legislative and judicial under a checks and balances system) are formally established by the Constitution. The executive and legislative are organized independently in all three spheres of government, while the judiciary is organized only at the federal and state and Federal District spheres.