Bourgeoisie: This term refers to the middle class, typically with reference to its perceived materialistic values or conventional attitudes. In Marxist contexts, it refers to the capitalist class who own most of society's wealth and means of production.
Class struggle: This is conflict between different classes in a community resulting from different social or economic positions and reflecting opposed interests.
Wage labor: This is the socioeconomic relationship between a worker and an employer, where the worker sells their labor power under a formal or informal employment contract.