Two of the key supranational institutions, the International monetary Fund (IMF) and the World Bank, were established following a conference of leading countries held at Bretton Woods in the USA in 1944 to establish a post-war framework to facilitate currency and economic stability. The IMF now has nearly 200 member countries. Both organizations are centered in Washington. The objectives of the two organizations were always clearly delineated. The IMF was intended to provide relatively short-term financing to stabilize economies that had got into trouble with their foreign currency debts and reserves. The World Bank to provide long-term financing to support development.
Both organizations have their own agendas and this has led to significant controversy over their roles, objectives and policies. I will tr y to avoid being judgmental and simply describe what their principal objectives are and how they seek to achieve them. In this day and age it is usually safer to talk about sex than it is about politics. Most people are more interested in the former than the latter in any case.
The third key supranational financial institution is the Bank for International Settlements (BIS). This is based in Basel, Switzerland and its establishment predates that of the IMF and World Bank.