Periphery countries are nations that are less economically developed and often rely on agriculture and raw material exports. They typically have weaker infrastructure, lower levels of industrialization, and limited access to technology compared to more developed nations. These countries often face challenges such as political instability and high levels of poverty. In the context of global economics, periphery countries are often contrasted with core countries, which are more industrialized and economically powerful. The term is part of the world-systems theory, which was developed by sociologist Immanuel Wallerstein to explain the dynamics of global trade and economic relationships.