World-systems theory is a sociological perspective that analyzes the global economic system as a complex network of interdependent relationships. It categorizes countries into three main groups: core, semi-periphery, and periphery. Core countries are economically developed and dominate global trade, while peripheral countries are less developed and often exploited for their resources. This theory, developed by sociologist Immanuel Wallerstein, emphasizes that economic and political power is unevenly distributed across the globe. It suggests that the interactions between these groups shape global inequalities and influence social, political, and economic dynamics worldwide.