In political and social sciences, communism (from Latin communis, "common, universal") is the philosophical, social, political, and economic ideology and movement whose ultimate goal is the establishment of the communist society, which is a socioeconomic order structured upon the common ownership of the means of production and the absence of social classes, money, and the state.
Communism includes a variety of schools of thought, which broadly include Marxism and anarchism (anarcho-communism), as well as the political ideologies grouped around both. All of these share the analysis that the current order of society stems from its economic system, capitalism; that in this system there are two major social classes; that conflict between these two classes is the root of all problems in society; and that this situation will ultimately be resolved through a social revolution. The two classes are the working class—who must work to survive and who make up the majority within society—and the capitalist class—a minority who derives profit from employing the working class through private ownership of the means of production. The revolution will put the working class in power and in turn establish social ownership of the means of production, which according to this analysis is the primary element in the transformation of society towards communism. Critics of communism can be roughly divided into those concerning themselves with the practical aspects of 20th century communist states and those concerning themselves with communist principles and theory.
Marxism-Leninism and social democracy were the two dominant forms of socialism in the 20th century; social democracy advocates economic reform through gradual democratic legislative action rather than through revolution.