The cantons are federated states, have a permanent constitutional status and, in comparison with the situation in other countries, a high degree of independence. Under the Federal Constitution, all 26 cantons are equal in status, except that 6 (referred to often as the half-cantons) are represented by only one councillor (instead of two) in the Council of States and have only half a cantonal vote with respect to the required cantonal majority in referendums on constitutional amendments. Each canton has its own constitution, and its own parliament, government, police and courts. However, there are considerable differences between the individual cantons, most particularly in terms of population and geographical area. Their populations vary between 16,003 (Appenzell Innerrhoden) and 1,487,969 (Zürich), and their area between  (Basel-Stadt) and  (Grisons).