Stratification is always a hierarchy, a division of society. In this case, it is the division according to the principle of social belonging. There are many social strata or strata.
A stratum is a unit of division in stratification. Since the concept itself came from geology, a stratum is a layer, a layer, not only in the earth, but in society. All people, one way or another, belong to various social groups. There are an infinite number of them, if we take the various principles of division as a basis.
For example, strata can be distinguished depending on age, material wealth, property ownership. A professional musician, an amateur musician, just a listener - there will also be layers of sorts. In different historical periods, in different states, such a division could play a significant role in the life of all people. So, in India there were castes, in Russia - estates, in a later period - classes. Belonging to a particular group could determine a person's entire life, from birth to death. In the same India, the transition from one caste to another was impossible. In Russia, with great difficulty and luck, it was possible to "climb" the social ladder. But to grow from the well-to-do peasantry into the merchant class, the class of the petty bourgeoisie became real only closer to the 20th century.
But even now, stratification plays an important role in the social life of almost all people. Despite the proclamation of democratic principles, universal equality, in fact, it turns out that connections, financial situation, some types of activity allow you to get certain privileges. And society in one way or another turns out to be divided into layers, built in a hierarchy. In general, it looks like a division into elites and masses. Those. at the bottom of the social ladder are, for example, ordinary workers, higher are officials who can influence them, even higher are the ruling elite of a city, region, country, etc.
Division into layers can be carried out “horizontally”, for example, according to the type of activity. Thus, a well-known musician and a well-known sportsman can stand on the same rung of the “vertical” hierarchy, but at the same time they naturally belong to different social groups.
