A class system is a form of social stratification based on both social factors and individual achievement. Unlike a caste system, which is closed and based on ascription, a class system is relatively open, allowing for social mobility based on factors such as education, occupation, and personal success, though structural barriers still influence outcomes.

Bourdieu argued that educational institutions reward the 'cultural capital'—such as linguistic styles, habits, and knowledge—that students acquire from their families. Because schools value the culture of the dominant class, students from these backgrounds possess a 'hidden advantage' that translates into academic success. This process ensures that class privilege is transmitted across generations, as the education system validates the cultural assets of the elite while marginalizing those of the working class.

Assets represent a stock of wealth or capital held by an individual or household. Unlike income, which is a flow of money over time, assets are accumulated resources such as real estate, financial investments, and savings that contribute to an individual's net worth.

In modern industrial societies, occupation is a central indicator of social status. It serves as a proxy for educational attainment, income potential, and social prestige. Because work occupies a significant portion of adult life, the nature of one's job is a primary factor in how others perceive and categorize their social standing.

Karl Marx viewed social class primarily through an economic lens, specifically focusing on the ownership or lack of ownership of the means of production. In his analysis, the bourgeoisie own the factories and resources, while the proletariat must sell their labor. This relationship defines the fundamental class structure of capitalist society. While other theorists like Weber expanded on this, the specific definition provided is foundational to Marxist theory.

During the mid-twentieth century, the accumulation of massive capital through corporate ownership and financial assets allowed wealthy industrialists to ascend into the upper class. While they lacked the hereditary status of the traditional aristocracy, their immense economic power and control over major industries and financial institutions effectively integrated them into the highest tier of the social hierarchy.

Sociological research on social interaction suggests that people tend to associate with others who share similar socioeconomic backgrounds, education levels, and lifestyles. This phenomenon, often called homophily, reinforces social stratification and influences the formation of social networks.

In many sociological frameworks, social class is viewed as a primary determinant of the nature, frequency, and quality of social relations. Individuals within the same social class often share similar lifestyles, values, and opportunities, which facilitates interaction and the formation of social networks, thereby linking social relations directly to class position.

Peter Saunders suggests that in modern societies, social and economic factors are the primary drivers of stratification, rather than cultural or ethnic differences. This perspective emphasizes the importance of economic resources and social status in determining an individual's position within the social hierarchy.

A class system is an open system of stratification where social standing is based primarily on economic factors and individual achievement. Unlike caste or slavery systems, which are closed, a class system permits individuals to move up or down the social hierarchy based on their efforts and opportunities.