Totalitarianism, authoritarianism, and fascism are all forms of government. And defining different forms of government isn't as easy as it might seem.
The governments of all nations have an official form as designated in the U.S. Central Intelligence Agency’s World Factbook. However, a nation’s own description of its form of government can often be less than objective. For example, while the former Soviet Union declared itself a democracy, its elections were not “free and fair” as only one party with state-approved candidates were represented. The USSR was more correctly classified as a socialist republic.