Totalitarian governments are very different from the governments in liberal democracies. The totalitarian governments of the mid-20th century were different from the liberal democracies largely in the amount of freedom that they afforded to their people.
In liberal democracies, people are supposed to have the maximum possible amount of freedom. Liberal democracies have a very strong regard for human rights. The government is supposed to stay out of people’s lives as much as possible. The people have the right to say whatever they want. They can criticize their governments as much as they like. This was true of liberal democracies like the United States in the mid-20th century. A person like Joseph McCarthy, for example, could accuse the Truman administration of harboring communists. African Americans in the 1950s and 1960s could engage in massive protests against laws that they disliked. There were, of course, huge protests against the Vietnam War. All of this is characteristic of liberal democracies.
By contrast, totalitarian governments like those of the Soviet Union and Nazi Germany try to control every aspect of their people’s lives. They try to control or at least strongly influence their religious beliefs. They prevent them from speaking their minds on many topics. They try to limit the sorts of arts and entertainment that they can consume. They have secret police forces to enforce these sorts of limits. It would have been unthinkable for anyone to be as critical of Hitler or Stalin as McCarthy was of Truman. It would have been inconceivable for the Nazis to allow mass protests of their annexation of the Sudetenland. This sort of control is characteristic of totalitarian states.
Thus, the totalitarian governments of the mid-1900s were very different from the liberal democracies of the time.