In the Marxist understanding, communism is the endpoint of human social evolution which will inevitably come into fruition through economic and social advances in socialism. Socialism, being the new order established after the demise of capitalism, is herein characterized by the working class having state power and undertaking the process of abolishing capitalist property and economic relations and establishing social (i.e. public, collective) ownership and management of society’s political, economic, and cultural institutions. In accordance with the socialized processes of production, appropriation also becomes socialized as goods and services become consumed on a social basis with free access for the individual.
Communism becomes fully realized when the distinction between classes is no longer possible and therefore the state, which has been used as an instrument of class dictatorship, no longer exists. In the communist economy, production and consumption are fully socialized, and the processes for which are advanced into maximized automation, efficiency, and recycling. This results in the end of individual money calculation, hence relationships between individuals being based on free association and free access to all goods and services according to need. ~~source: Wikipedia