The working class, sometimes incorrectly referred to as the middle class, includes all employees who are compensated with wage or salary-based contracts. Working-class occupations (see also "Designation of workers by collar colour") include blue-collar jobs, and most pink-collar jobs. Members of the working class rely exclusively upon earnings from wage labour; thus, according to more inclusive definitions, the category can include almost all of the working population of industrialized economies, as well as those employed in the urban areas (cities, towns, villages) of non-industrialized economies or in the rural workforce.
As with many terms describing social class, working class is defined and used in many different ways. One definition, used by many socialists, is that the working class includes all those who have nothing to sell but their labour. These people used to be referred to as the proletariat. In that sense, the working class today includes both white and blue-collar workers, manual and menial workers of all types, excluding only individuals who derive their livelihood from business ownership and the labour of others. The term, which is primarily used to evoke images of laborers suffering "class disadvantage in spite of their individual effort", can also have racial connotations. These racial connotations imply diverse themes of poverty that imply whether one is deserving of aid.
When used in non-Socialist contexts, however, it often refers to a section of society dependent on physical labour, especially when compensated with an hourly wage (for certain types of science, as well as journalistic or political analysis). For example, the working class is loosely defined as those without college degrees. Working-class occupations are then categorized into four groups: unskilled labourers, artisans, outworkers, and factory workers.
A common alternative is to define class by income levels. When this approach is used, the working class can be contrasted with a so-called middle class on the basis of differential terms of access to economic resources, education, cultural interests, and other goods and services.