Title: Sahara
Content:   The Sahara (, ; الصحراء الكبرى, aṣ-ṣaḥrāʼ al-kubrá, 'the Greatest Desert') is a desert on the African continent. With an area of 9200000 km2, it is the largest hot desert in the world and the third largest desert overall, smaller only than the deserts of Antarctica and the northern Arctic. The name "Sahara" is derived from the Arabic word for "desert" in the feminine irregular form, the singular ṣaḥra' (صحراء ), plural ṣaḥārā (صَحَارَى    ), ṣaḥār ( صَحَار ), ṣaḥrāwāt ( صَحْارَاوَات ), ṣaḥāriy ( صَحَارِي ). The desert comprises much of North Africa, excluding the fertile region on the Mediterranean Sea coast, the Atlas Mountains of the Maghreb, and the Nile Valley in Egypt and Sudan. It stretches from the Red Sea 
Title: Desert
Content:  areas with their herds, moving to new pastures as seasonal and erratic rainfall encouraged new plant growth. They took with them their tents made of cloth or skins draped over poles and their diet included milk, blood and sometimes meat.  The desert nomads were also traders. The Sahara is a very large expanse of land stretching from the Atlantic rim to Egypt. Trade routes were developed linking the Sahel in the south with the fertile Mediterranean region to the north and large numbers of camels were used to carry valuable goods across the desert interior. The Tuareg were traders and 
Title: Algerian Desert
Content:  The Algerian Desert (الصحراء الجزائرية) is located in north-central Africa and is part of the Sahara Desert. The desert occupies more than four-fifths of Algerian territory. Its expansion starts from the Saharan Atlas as a stony desert, gradually changing into a sand dune desert inland. The plateau of the Tassili n'Ajjer is located in the southeast, and its outstanding collection of prehistoric rock art saw it added to the UNESCO World Heritage List in 1982. Cities and towns such as Ouargla, Adrar, and particularly In Salah are among the hottest places in the Sahara. Annual average rainfall is well below 100 mm in the northernmost part but the center and the southern part receive much less than 50 mm.
Title: North Africa
Content:  desert, which is the largest sand desert in the world. In places the desert is cut by irregular watercourses called wadis—streams that flow only after rainfalls but are usually dry. The Sahara's major landforms include ergs, large seas of sand that sometimes form into huge dunes; the hammada, a level rocky plateau without soil or sand; and the reg, a level plain of gravel or small stones. The Sahara covers the southern part of Algeria, Morocco and Tunisia, and most of Libya. Only two regions of Libya are outside the desert: Tripolitania in the northwest and Cyrenaica in the northeast. Most of Egypt is also desert, with the exception of the Nile 
Title: Sahara desert (ecoregion)
Content:  The Sahara Desert is the world's largest hot, non-polar desert and is located in North Africa. It stretches from the Red Sea to the Atlantic Ocean. The vast desert encompasses several ecologically distinct regions. The Sahara Desert ecoregion covers an area of 4,619,260 km2 in the hot, hyper-arid center of the Sahara, surrounded on the north, south, east, and west by desert ecoregions with higher rainfall and more vegetation. The North Saharan steppe and woodlands ecoregion lies to the north and west, bordering the Mediterranean climate regions of Africa's Mediterranean and North Atlantic coasts. The North Saharan steppe and woodlands receives more regular 
Title: Sahel
Content:  The Sahel (ساحل sāḥil, "coast, shore") is the ecoclimatic and biogeographic realm of transition in Africa between the Sahara to the north and the Sudanian savanna to the south. Having a semi-arid climate, it stretches across the south-central latitudes of Northern Africa between the Atlantic Ocean and the Red Sea. The Sahel part of Africa includes from west to east parts of northern Senegal, southern Mauritania, central Mali, northern Burkina Faso, the extreme south of Algeria, Niger, the extreme north of Nigeria, the extreme north of Cameroon and Central African Republic, central Chad, central and southern Sudan, the extreme north of South Sudan, Eritrea and the extreme north of Ethiopia. Historically, the western part of the Sahel was sometimes known as the Sudan region (bilād as-sūdān بلاد السودان "lands of the Sudan"). This belt was roughly located between the Sahara and the coastal areas of West Africa.
Title: Geography of Africa
Content:  south of desert is the plains region known as the Sahel. The arid region, the Sahara — the largest hot desert in the world, covering 9000000 km2 — extends from the Atlantic to the Red Sea. Though generally of slight elevation, it contains mountain ranges with peaks rising to 2400 m Bordered N.W. by the Atlas range, to the northeast a rocky plateau separates it from the Mediterranean; this plateau gives place at the extreme east to the delta of the Nile. That river (see below) pierces the desert without modifying its character. The Atlas range, the north-westerly part of the continent, between its seaward and landward heights encloses elevated steppes in places 160 km broad. From the inner slopes of the plateau numerous wadis take a direction towards the Sahara. The greater part of that now desert region is, indeed, furrowed by old water-channels.
Title: Western Sahara
Content:  Western Sahara (الصحراء الغربية aṣ-Ṣaḥrā' al-Gharbiyyah; ; Sáhara Occidental) is a disputed territory on the northwest coast and in the Maghreb region of North and West Africa. About 20% of the territory is controlled by the self-proclaimed Sahrawi Arab Democratic Republic, while the remaining 80% of the territory is occupied and administered by neighboring Morocco. Its surface area amounts to 266000 km2. It is one of the most sparsely populated territories in the world, mainly consisting of desert flatlands. The population is estimated at just over 500,000, of which nearly 40% live in Laayoune, the largest city in Western Sahara. Occupied by Spain until 1975, Western Sahara has been on the United 
Title: Sahara
Content:  Sahara is bounded by the Sahel, a belt of dry tropical savanna with a summer rainy season that extends across Africa from east to west. The southern limit of the Sahara is indicated botanically by the southern limit of Cornulaca monacantha (a drought-tolerant member of the Chenopodiaceae), or northern limit of Cenchrus biflorus, a grass typical of the Sahel. According to climatic criteria, the southern limit of the Sahara corresponds to the 150 mm isohyet of annual precipitation (this is a long-term average, since precipitation varies annually). Important cities located in the Sahara include Nouakchott, the capital of Mauritania; Tamanrasset, Ouargla, Béchar, Hassi Messaoud, Ghardaïa, and El Oued in Algeria; Timbuktu in Mali; Agadez in Niger; Ghat in Libya; and Faya-Largeau in Chad.
Title: Sahara
Content:  south. It covers 1675300 km2 in Algeria, Egypt, Libya, Mauritania, Morocco, and Tunisia. The Sahara Desert ecoregion covers the hyper-arid central portion of the Sahara where rainfall is minimal and sporadic. Vegetation is rare, and this ecoregion consists mostly of sand dunes (erg, chech, raoui), stone plateaus (hamadas), gravel plains (reg), dry valleys (wadis), and salt flats. It covers 4639900 km2 of: Algeria, Chad, Egypt, Libya, Mali, Mauritania, Niger, and Sudan. The South Saharan steppe and woodlands ecoregion is a narrow band running east and west between the hyper-arid Sahara and the Sahel savannas to the south. Movements of the equatorial Intertropical Convergence Zone (ITCZ) bring summer rains during July and August which average 100 to 200 mm but vary greatly from 

Question: what is the significance of the sahara desert?
Answer: the largest hot desert.