Totalitarianism is a form of government and a political system that seeks to assert total control over the lives of its citizens. It prohibits all opposition parties, outlaws individual and group opposition to the state, and exercises an extremely high, if not complete, degree of control over various aspects of social life, including the economy, education, arts, science, and the private lives and morals of citizens. Totalitarian regimes are characterized by extreme political repression, human rights violations, a lack of democratic ideals, personality cultism around the ruling party, absolute control over the economy, censorship, mass surveillance, and limited freedom of movement. They typically pursue a special goal to the exclusion of all others, with all resources directed toward its attainment, regardless of the cost.

Totalitarianism is distinguished from other forms of government, such as dictatorship, despotism, or tyranny, by its supplanting of all political institutions with new ones and its sweeping away of all legal, social, and political traditions. The term "totalitarianism" is also sometimes used to refer to movements that manifest extreme dictatorial and fanatical methods, such as cults and forms of religious extremism.

In summary, totalitarianism is a form of government that seeks to exert complete control over all aspects of individual life and society, often at the expense of individual freedom and human rights.