Marx's Concept of Man. Erich Fromm 1961
Alienation has to do with what happens to workers under the conditions of wage labor (the industrial division of labor). Marx pointed out that there are four aspects to alienation. Wage laborers are alienated from their products, from their labor, from their “species-being” (human essence) and from other workers.
Alienation means the lack of power, control and fulfillment experienced by workers in capitalist societies which the means of producing goods are privately owned and controlled
Saul McLeod • Marx's Theory of Alienation In Sociology
Capitalism, for Marx, is a world in which the worker is dominated by the products of his labor, which have taken on the shape of an alien being, capital.