A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than 400 millimetres (16 in).
In geography, an oasis (plural: oases) or cienega (Southwestern United States) is an isolated area of vegetation in a desert, typically surrounding a spring or similar water source. Oases also provide habitat for animals and even humans if the area is big enough.
In physical geography, a steppe is an ecoregion, in the montane grasslands and shrublands and temperate grasslands, savannas, and shrublands biomes, characterized by grassland plains without trees apart from those near rivers and lakes.
The ten largest deserts Rank Desert Area (km²) Area (mi²)
1 Antarctic Desert (Antarctica) 13,829,430 5,339,573
2 Arctic Desert (Arctic) 13,726,937 1,003,600+
3 Sahara Desert (Africa) 9,100,000+ 3,320,000+
4 Arabian Desert (Middle East) 2,330,000 900,000
5 Gobi Desert (Asia) 1,300,000 500,000
6 Kalahari Desert (Africa) 900,000 360,000
7 Patagonian Desert (South America) 670,000 260,000
8 Great Victoria Desert (Australia) 647,000 250,000
9 Syrian Desert (Middle East) 520,000 200,000
10 Great Basin Desert (North America) 492,000 190,000