This document provides an overview of Karl Marx and Marxist theory. It introduces Karl Marx, his key concepts and ideologies such as capitalism, class struggle, exploitation, and alienation. It describes the two main classes in capitalist society according to Marx: the bourgeoisie and the proletariat. It also outlines the different types of Marxism, criticisms of Marxist ideas, and Marx's contributions to modern social and economic theory, such as the conflict model of society and origins of power and alienation.