What is core periphery?

The core-periphery theory states that there is a strong, centralized group that holds power and makes most of the decisions within a society, and an outside, periphery, group that is effected by those decisions. In Wallerstein's original theory, he looked at countries that are capitalist, have an abundance of natural resources and a strong economy as the core countries and viewed countries with weak economies and lacking a strong government as periphery country. In his theory, Wallerstein describes how the core countries exploit the periphery countries.