What is the proletariat and who are the proletarians?

It's probably hard to find a person in our country who hasn't heard the word "proletariat," but not everyone knows what it means. The average person associates proletarians with workers depicted on posters. Those familiar with Marxism only through the Communist Manifesto believe that proletarians are wage laborers who own no property.
Moreover, some might argue that proletarians in the old sense no longer exist: dispossessed workers with nothing to lose but their chains are a thing of the 19th century, Marx is obsolete, and socialism is no longer needed. And these people would also be wrong. Leftist laymen also cannot clearly define the term: some classify all wage workers as proletarians, others only those who earn their living through physical labor. And this, too, would be incorrect.

The working class includes all those who earn a living by selling their ability to labor. Two strata can be distinguished within the working class: the labor aristocracy and the proletariat. The labor aristocracy differs from the proletariat in that it earns its wages by exploiting other workers.
In the modern world, the labor aristocracy includes top managers and the majority of workers in the so-called "First World" countries. The majority of a top manager's salary is derived from surplus value generated by the labor of other workers. Meanwhile, the high standard of living in First World countries is supported by the labor of workers in developing countries. Thus, a proletarian is a worker who does not benefit from exploitation.
In his notes to Marx's Capital, Engels refers to, for example, trade workers who do not produce surplus value as proletarians. In general, for Marx and Engels, the working class and the proletariat were often synonymous. Today, however, the working class is polarized due to rising prosperity and the global division of labor. The proletariat today is a part of the working class, not a synonym for it.
Moreover, many modern experts believe that the very concept of “proletariat” has remained, rather, in stories and is associated, to a large extent, with the Soviet era and one of its main slogans: "Workers of the world, unite!" But in any case, the question of terminology is debatable, especially when the trail of history is mixed into the matter.
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