p 1 here are both natural (sex, age and race) and social distinctions between people living in society. Unlike natural ones, social distinctions are the result of the historical development of society. For example, class distinctions appear when the primitive-communal system disintegrates and private ownership, economic inequality and exploitation come into being. Social distinctions form the basis of the social differentiation ( division) of society. Stable social communities (clan, tribe, nationality, nation, family, class, profession, etc.) emerge in different ways and in different historical periods.

p Such communities have existed in the history of mankind for hundreds and thousands of years. The most important of them (classes, nationalities and nations) act as subjects in the historical process : it is through their activity that major historical events occur.

p Connected with one another and mutually interdependent, these communities form the structure of society.

Each socio-economic formation has a specific social structure which is dependent on the mode of production of material benefits. It alters when there is a change in the mode of production.