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. 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]