Dependency Theory is an economic and social theory that suggests that the resources and wealth of developing countries are exploited by developed nations, leading to a cycle of dependency. It argues that the global economic system is structured in a way that benefits wealthy countries while hindering the growth and development of poorer nations. The theory emerged in the mid-20th century, influenced by thinkers like André Gunder Frank and Raúl Prebisch. It emphasizes that to achieve true development, countries must break free from this dependency and create self-sustaining economies, rather than relying on foreign investment and aid.