Proletarian internationalism, sometimes referred to as international socialism, is the perception of all proletarian revolutions as being part of a single global class struggle rather than separate localized events. It is based on the theory that capitalism is a world-system and therefore the working classes of all nations must act in concert if they are to replace it with communism.

Socialism is an economic and political philosophy encompassing diverse economic and social systems characterised by social ownership of the means of production, as opposed to private ownership. It describes the economic, political, and social theories and movements associated with the implementation of such systems. Social ownership can take various forms, including public, community, collective, cooperative, or employee. Traditionally, socialism is on the left wing of the political spectrum. Types of socialism vary based on the role of markets and planning in resource allocation, and the structure of management in organizations.