In politics, a regime (also spelled régime) is a system of government that determines access to public office, and the extent of power held by officials. The two broad categories of regimes are democratic and autocratic. Autocratic regimes can be further divided into types such as dictatorial, totalitarian, absolutist, monarchic, and oligarchic. A key similarity across all regimes is the presence of rulers of both formal and informal institutions, which interact dynamically to adapt to changes to their environment[1][2][3] The CIA website also has a complete list of every country in the world with their respective types of regimes.[4]