The main difference between the totalitarianism that arose after World War I and earlier forms of authoritarianism is that it allowed much less individual freedom.
Authoritarianism is a term political scientists use for a worldview that values orderliness and authority, and distrusts outsiders and social change.
Totalitarianism is a political concept of a mode of government which prohibits opposition parties, restricts individual opposition to the state and its claims, and exercises an extremely high degree of control over public and private life. It is regarded as the most extreme and complete form of authoritarianism.