This document provides an overview of world systems theory, which examines how structures shape the flow of people, goods, and ideas globally. It discusses key concepts such as the core, semi-periphery, and periphery of the global economic system. World systems theory views the global economy as a single world-economy larger than any political unit, with economic relations between parts being most important. It also examines resistance to the world system, modernity, global flows of different types, and the central role of media and cultural imagination.