West African refers to the region located in the western part of Africa that encompasses 16 countries. This region has a rich history and cultural heritage that has influenced much of Africa. There are several synonyms for the term West African, including Sahelian, Sudano-Sahelian, Coastal West Africa, and Guinea Coast. Sahelian refers to the region that is characterized by the semi-arid climate with sparse vegetation. Sudano-Sahelian is a term used to describe the transitional region between the Sahel and the tropical rainforest. Coastal West Africa refers to the region that is characterized by the Atlantic Ocean coastline. Guinea Coast refers to the region that is made up of countries that once had the Guinea currency.