This division of Africa has arisen from the perception of North Africa as predominantly Arab in ethnicity or culture and the perception of sub-Saharan Africa as predominantly black in ethnicity or culture, and from the geographic separation of the two regions by the sparsely populated Sahara Desert.
The exact position of the dividing line between the two regions is not clear. However, according to one classification of the two regions, sub-Saharan Africa includes forty-eight nations. Forty-two of these nations are on the African mainland. In addition, four island nations in the southwest Indian Ocean (Madagascar, The Comoros, Mauritius, and Seychelles) and two island nations in the Atlantic Ocean (Cape Verde and Sao Tome and Principe) are considered part of Africa. According to this classification scheme, the countries of sub-Saharan Africa are: