World-Systems Theory is based on the work of Karl Marx. World-Systems Theory was made into a developed set of ideas by Immanuel Wallerstein.
World-systems theory is also referred to as world-systems analysis or the world-systems perspective.
World-Systems Theory shows that capitalism is not just an economic system bounded by national borders highlighting class inequality.
According to World-Systems Theory, capitalism must be seen as involving relationships among nations and these relationships are based on inequality.
Again, according to World Systems Theory, those nations which developed capitalistic economies early then went on to dominate other nations through colonialism and colonization or simply through linking the economies of the nations in ways that favored the more dominant nation and placed the others into a condition of dependency on the dominant nation.
This state of dependency, according to World Systems Theory, tended to hamper the development of the other economies.
The world-system perspective, indebted to Marxism, views capitalism as the engine of development in the modern era, and sees societies as bearing at least a peripheral relationship to capitalist expansion.
World-Systems Theory is a macro-scale approach to world history and social change that emphasizing that the world-system should be the primary unit of social analysis and not nation states.