Marx tried to understand how the capitalist society works, how it arose out of feudalism, and where it is likely to lead. Concentrating on the social and economic relations in which people earn their livings, Marx saw behind capitalism a struggle of two main classes: the capitalists, who own the productive resources, and the workers or proletariat, who sell their labor force to survive. Marxism is basically Marx’s analysis of the complex and developing relations between these two classes.