Rwanda, officially the Republic of Rwanda, is a sovereign state in Central and East Africa and one of the smallest countries on the African mainland. Located a few degrees south of the Equator, Rwanda is bordered by Uganda, Tanzania, Burundi and the Democratic Republic of the Congo. Rwanda is in the African Great Lakes region and is highly elevated; its geography is dominated by mountains in the west and savanna to the east, with numerous lakes throughout the country. The climate is temperate to subtropical, with two rainy seasons and two dry seasons each year.
The population is young and predominantly rural, with a density among the highest in Africa. Rwandans are drawn from just one cultural and linguistic group, the Banyarwanda, although within this group there are three subgroups: the Hutu, Tutsi and Twa. The Twa are a forest-dwelling pygmy people descended from Rwanda's earliest inhabitants. Scholars disagree on the origins of and differences between the Hutu and Tutsi; some believe differences are derived from former social castes within a single people, while others believe the Hutu and Tutsi arrived in the country separately, and from different locations.