Why do people assume a link between communism and the nazi regime?

[arber47]

Communist is far left-wing whilst the Nazi party is a prime example of an extreme-right wing party. The Soviets lead the battle against the Nazis in World War 2 and were the true reason for the survival of France. Communism is also the ideology that the people own the state, that is, property of the state is owned by all the people of the country. The Nazi ideology was 'follow the path of one man for success'. So why do people actually think they're almost the same?