The working class (also labouring class and proletariat) are the people employed for wages, especially in manual-labour occupations and in skilled, industrial work. Working-class occupations include blue-collar jobs, some white-collar jobs, and most service-work jobs. The working class only rely upon their earnings from wage labour, thereby, the category includes most of the working population of industrialized economies, of the urban areas (cities, towns, villages) of non-industrialized economies, and of the rural workforce.
In Marxist theory and socialist literature, the term working class is often used interchangeably with the term proletariat, and includes all workers who expend both physical and mental labour (salaried knowledge workers and white-collar workers) to produce economic value for the owners of the means of production (the bourgeoisie in Marxist literature). Since working-class wages can be very low, and because the state of unemployment is defined as a lack of independent means of generating an income and a lack of wage-labour employment, the term working class also includes the lumpenproletariat, unemployed people who are extremely poor.
As with many terms describing social class, working class is defined and used in many different ways. The most general definition, used by Marxists and socialists, is that the working class includes all those who have nothing to sell but their labor-power and skills. In that sense it includes both white and blue-collar workers, manual and mental workers of all types, excluding only individuals who derive their income from business ownership and the labor of others.