Since the second world war, the International Monetary Fund (IMF) and the World Bank have attempted to help countries in financial difficulties by providing low interest loans. This week the two Bretton Woods institutions have been holding their annual meetings in the Moroccan town of Marrakech - the first time they’ve been on African soil in 50 years. The two institutions divide opinion. Some people believe they have had a positive impact. But others say the organisations are dominated by the west and need reform to make them fairer to developing countries. So, what do we really know about the World Bank and IMF?