Relations of Production allows one to understand both the state and the market as two different forms of expression of capitalist relations and thus a particular historical form of class struggle. It refer to the social relations specific to a particular mode of production, and reserved division of labour for the concrete, structural composition and organization of production relations. It is a concept frequently used by Karl Marx and Friedrich Engels in their theory of historical materialism, and in Das Kapital. Marx and Engels typically use the term to refer to the socioeconomic relationships characteristic of a specific epoch.