Stalin was a communist. Putin is more of a fascist. Both were/are totalitarian dictators. The difference, IMHO, although fascism is hard to define, is more economics - that fascism is like a marriage between corporate capitalism and a totalitarian political system. Stalin had a central planning socialist economic system. Putin's Russia is very much an oligarchic dictatorship. Hitler was like a hybrid of the two systems. It is hard to make a definitive definition of terms like this because every situation in every country is unique.