Socialism: We are divided by class. The bourgeoisie oppress us and will never share their power, our only choice is revolution and eradication. (Communism will come after the revolution)
National Socialism (Nazis): We are divided by nation. The Jews oppress us and will never share their power, our only choice is revolution and eradication. (Add in Brits, French, Czech, Poles...)
Race Socialism: We are divided by race. The Whites oppress us and will never share their power, our only choice is revolution and eradication.
Sex Socialism: Surely you get the point by now.
I realize this is off topic, where do I put it?
Yep. The big difference is that while both fascism and communism lead to failure eventually, communism is MUCH more successful at gaining power first.