The Kalahari has vast areas covered by red-brown sands and has no permanent surface water. Drainage is by dry valleys, seasonally inundated pans, and the large salt pans of the Makgadikgadi Depression in Botswana and Etosha Pan in Namibia. However, the Kalahari is not a true desert. Parts of the Kalahari receive over 250 mm of erratic rainfall annually and are quite well vegetated; it is only truly arid in the south-west (under 175mm of rain annually) making the Kalahari a fossil desert. Summer temperatures in the Kalahari range from 20 - 40 °C. In winter, the Kalahari has a dry, cold climate with frosts at night. The average low winter temperature can be below 0 °C.
The Kalahari has a number of game reserves - the Central Kalahari Game Reserve (CKGR, the world's second largest protected area), Khutse Game Reserve and the Kgalagadi Transfrontier Park. Animals that live in the region include brown hyenas, lionss, meerkats, several species of antelope (including the oryx or gemsbok and the tsamma), and many species of bird and reptile. Vegetation in the Kalahari consists mainly of grasses and acacias but there are over 400 identified plant species present.
The area is the ancestral land of the Bushmen peoples. There are many distinct tribes, and they have no collective name for themselves. The names San and Basarwa are sometimes used, but the people themselves dislike these names (San is a Khoi word meaning outsider, and Basarwa a Herero word meaning person who has nothing) and prefer the name "Bushman". They are thought to have been the first human inhabitants of Southern Africa; there is evidence that they have been living there continuously as nomadic hunter-gatherers for at least twenty thousand years.
In 1965 the Botswanan government forced all the Bushmen from their lands within the borders of that country and "resettled" them in fixed encampments. The government has given several different justifications for their action: that it was for purposes of nature conservation; that it was too expensive to continue to supply the Bushmen with water (the water table had been lowered by farming and other development); that it was "to enable them to share in the wealth of the country"; that it was for their own good to become settled and "civilised". The campaign group Survival International have alleged that the real reason for the re-settlement is to free up the land for diamond mining, but a different group campaigning for the rights of the Bushmen, Ditshwanelo (the Botswanan Centre for Human Rights), dispute this, claiming that the Government's motives are genuine, but misguided.
There are large coal, copper, and nickel deposits in the region. One of the largest diamond mines in the world is located at Orapa in the Makgadikgadi, northeastern Kalahari.
Kalahari is derived from the Tswana word "Kgalagadi", meaning "the great thirst".