World-systems theory is a perspective in sociology and other social sciences that views the world as a complex system of interconnected and interdependent economic, political, and cultural relationships. Developed by sociologist Immanuel Wallerstein in the 1970s, world-systems theory seeks to explain patterns of global inequality, development, and change by examining the historical evolution and structure of the world economy.

Key aspects of world-systems theory include:

1. Core-Periphery Structure: World-systems theory conceptualizes the global economy as divided into core, semi-peripheral, and peripheral regions. Core countries are characterized by advanced industrial economies, technological innovation, and economic dominance, while peripheral countries are economically dependent on core countries and often serve as sources of cheap labor and raw materials.
2. Unequal Exchange: World-systems theory highlights the unequal exchange of resources, capital, and labor between core and peripheral regions. It argues that core countries benefit from the exploitation of peripheral countries through processes such as colonialism, imperialism, and globalization, which perpetuate economic disparities and dependency relationships.
3. Dependency Theory: World-systems theory is closely related to dependency theory, which emphasizes the historical and structural factors that contribute to underdevelopment and dependency in peripheral countries. It argues that peripheral countries are disadvantaged by their integration into the global capitalist system, which prioritizes the interests of core countries and perpetuates dependency relationships.
4. World-Economy Analysis: World-systems theory employs a macro-level approach to analyze the dynamics of the world economy as a single, interconnected system. It examines long-term historical trends, such as the rise and fall of empires, the spread of capitalism, and the emergence of global trade networks, to understand patterns of economic development, imperialism, and social change.
5. Globalization and Resistance: World-systems theory considers the role of globalization in reshaping the structure and dynamics of the world economy. It examines how processes such as transnational corporations, international trade agreements, and financial flows contribute to the integration and stratification of the world-system, as well as the resistance and mobilization of social movements against global inequalities and injustices.
6. Critiques and Debates: World-systems theory has been subject to critiques and debates within the social sciences. Critics argue that it oversimplifies the complexity of global relations, neglects the agency of individuals and local actors, and overlooks cultural, political, and environmental factors in shaping social change. Proponents, however, argue that world-systems theory provides a valuable framework for understanding the structural roots of global inequality and offers insights into strategies for social transformation and emancipation.

Overall, world-systems theory offers a critical perspective on the dynamics of the global economy and the historical processes that have shaped patterns of inequality and development across regions. It fosters interdisciplinary research and dialogue among scholars, activists, and policymakers to address the root causes of global injustices and envision alternative pathways to a more equitable and sustainable world.