Peripheral countries, according to world-systems theory developed by Immanuel Wallerstein, are those countries that have a marginal and often subordinate role in the global economy and are thus dependent on the core-producing (wealthy, industrialised) societies for their trading relationships, often serving as sources of raw materials, cheap labor, and markets for core countries' products. These countries typically have less diversified economies, weaker state institutions, and lower levels of industrialisation and technological development compared to core and semi-peripheral nations. The economic relationships between core and peripheral countries are often characterised by unequal exchange, where peripheral nations may be exploited for their resources and labor, hindering their own economic development and perpetuating global inequalities.