Class is a term that in the social sciences is used to separate people into groups based on economic and social criteria. The concept was established in the 1800s as a basis for both classical liberalism and early socialism. The concept of class has been the most relevant in Marxist theory, where social classes have different roles in or in relation to the production of goods and services. What is in focus is the power over ownership, and in Marxist thought the concept is also a cornerstone of a theory concerning social mobilisation, so-called class struggle, aimed to change the economic power structure in society.

Other concepts of class have subsequently been developed in the field sociology, focusing on the positions of social classes not only in the production but also in relation to consumption patterns, education and basic values. Thus, there is an emphasis on exploring the economic conditions faced by various groups – what they own, how they earn a living and what consumption opportunities they have. These factors determine their potential to shape their own lives and give society an unequal structure.

Feminist and antiracist critiques of traditional Marxist theory have made the point that a too narrow focus on economic inequality and the capitalist production model can result in a view of class that excludes other groups than those that fit the stereotypical notion of the white, masculine and muscular worker (see also hegemony, racialisation, whiteness). Class relations cannot be understood in isolation from other power structures, such as gender, ethnicity, functionality and sexuality (see also heteronormativity). For example, a working class background often implies different things for women and men, since the unpaid home and family work that women traditionally have engaged in has not been recognised as labour of economic value. That men have been considered breadwinners has been taken to justify a gendered division of work where the position of women in the labour market is underpaid and less secure. Research also describes how power relations based on class and ethnicity bleed into and reinforce each other. The phenomenon of immigrant women and men being overrepresented in occupations with low salaries and poor working conditions such as taxi, cleaning and restaurant services is sometimes referred to as ethnification of the labour market. What can be understood as class inequality from one perspective can also be seen as an expression of power relations from the angle of ethnicity or origin.

Class has cultural dimensions as well, as the working and middle classes are characterised by different norms and values. Throughout history, the working class has been portrayed as dangerous, unrestrained, vulgar, disrespectful or revolutionary. Sometimes this is described as class contempt. Norms and ideals prescribing modesty, education and good taste reinforce the cultural and economic dominance demonstrated by the middle class. Research has shown how this generates an identity among women and men in the working class where they are forced to fight to gain respect in the eyes of others. Including these dimensions in the analysis enables a broader understanding of class than that made possible by strict studies of economic conditions.