A “Marxist” refers to those individuals who ascribe to the political and economic theories espoused by the 19th century German philosopher Karl Marx. Marx, best remembered for The Communist Manifesto, wrote that economics had become a struggle between the bourgeoisie and the proletariat.
There is perhaps, no single definition of Marxism that suffices. Marx believed that economics was the primary driving force in history and that the modes of production were the originator of all social relations. As the modes of production increased in complexity, thanks to the Industrial Revolution, inefficiencies in social organization became manifest in society. These inefficiencies formed the basis of class struggle, specifically the struggle between the workers (proletariat) and the capitalists (bourgeoisie).
Marxists believe that the struggle between classes is ultimately a political struggle. The capitalists, the smaller societal group, eventually end up controlling both the means of production and the surplus of wealth created by labor. Marxists hold that this imbalance will eventually lead to revolution.
Marxism believes that revolution will eventually lead to the establishment of communism, where the workers control the means of production. Communism is ideally, a classless society in which everyone contributes according to his or her ability. Marxism served as the intellectual underpinning of the 1917 Soviet Revolution.