Communism is a global, classless society based on social ownership of the means of production that we expect will supersede capitalism.
Such a superior society based on mutual regard rather than profit is made possible by capitalism itself. On the one hand, the high level of economic development achieved under capitalism means that communism would not be shared poverty and toil but rather its opposites - shared abundance and work done willingly, that fully develops the individual's creative powers. On the other hand, capitalism creates the agent of change, the proletariat. This is a class to which most people belong once capitalism is fully developed. It has no interest in the present system and is equipped by modern conditions to begin the struggle to transform society and itself.