In reference to the economic integration of less developed nations into the structures of a world economy (world system theory), regions consist of geographical areas that dominate the world economy and exploit the rest of the system.

Core regions.

Explanation:

In reference to the economic integration of less developed nations into the structures of a world economy (World Systems Theory), core regions consist of geographical areas that dominate the world economy and exploit the rest of the system. In the World Systems Theory, developed by Immanuel Wallerstein, there are three types of regions. The core regions, the semi-peripheral regions, and the peripheral regions. While the core regions dominate and exploit the rest of the system, the peripheral regions don't have  strong governments and are dependent on the core regions for capital.