Why did you include socialism in there? That would be like including anarchism, anarcho-capitalism, and liberalism together in the same question.
what's the line between socialism and communism? Karl Marx considered himself a socialist. The USSR was considered a socialism...
Well I could call myself a communist but that doesn't mean I am. I don't think anyone would doubt that there is a difference between the Union of Soviet Socialist Republics, which was communist, and Sweden, which is socialist/social democratic in nature. China calls itself a People's Republic but that doesn't mean squat when it comes to the actual running of the country. Socialism a different stream of thought from Communism, though they both grew out of the same mold. As always there are degrees of difference and there are seperations on the left just as there are on the right.