Complex sentence: The United Nations is a scheme devised by the United Nations Statistics Division (UNSD) based on the M49 coding classification, which divides the world into macro-geographical regions and subregions.
Split into simpler sentences: The United Nations geoscheme is a geoscheme that group countries into geographic groups devised by the United Nations Statistics Division (UNSD) based on the M49 coding classification. The UN scheme divides the world into macro-geographical regions and subregions.