Africa is the world's second-largest and second-most-populous continent. At about 30.2 million km² including adjacent islands, it covers six percent of the Earth's total surface area and 20.4 percent of the total land area. With 1.0 billion people, it accounts for about 15% of the world's human population. The continent is surrounded by the Mediterranean Sea to the north, both the Suez Canal and the Red Sea along the Sinai Peninsula to the northeast, the Indian Ocean to the southeast, and the Atlantic Ocean to the west. The continent includes Madagascar and various archipelagoes. It has 54 fully recognized sovereign states, 9 territories and two de facto independent states with limited or no recognition. Africa is the youngest continent in terms of its population - 50 percent of Africans are 19 years old or younger. Africa's name is derived from an ancient area in modern day Tunisia known as Ifriqiya or sunny place, in Tamazight. Algeria is the largest African country by area, and Nigeria is the largest by population. Africa, particularly central Eastern Africa, is widely accepted as the origin of humans and the Hominidae clade, as evidenced by the discovery of the earliest hominids and their ancestors, as well as later ones that have been dated to around seven million years ago – including Sahelanthropus tchadensis, Australopithecus africanus, A. afarensis, Homo erectus, H. habilis and H. ergaster – with the earliest Homo sapiens found in Ethiopia being dated to circa 200,000 years ago. Africa straddles the equator and encompasses numerous climate areas; it is the only continent to stretch from the northern temperate to southern temperate zones.
Hegyek, dombok között húzódó hosszanti mélyedés. (Pl.:Szalajka-völgy)
A földfelszín hegyekkel, vagy dombokkal körülvett nagyobb, tál alakú mélyedése. (Pl.: Kárpát-medence)
Fennsík (más néven plató vagy magasföld) az a síkság, amely tartósan 200 méter tengerszint feletti magasságon terül el. A fennsíkokon általában nem találhatóak nagyobb kiemelkedések, felületük viszonylag egységesnek mondható. Sok fennsík lejtős, fokozatosan átmegy alföldbe.