In geography, an oasis (/oʊˈeɪsɪs/; pl. oases /oʊˈeɪsiːz/) is a fertile land in a desert or semi-desert environment. Oases also provide habitats for animals and plants.The word oasis came into English from Latin: oasis, from Ancient Greek: ὄασις, óasis, which in turn is a direct borrowing from Demotic Egyptian. The word for oasis in the latter-attested Coptic language (the descendant of Demotic Egyptian) is wahe or ouahe which means a "dwelling place".Oases are made fertile when sources of freshwater, such as underground rivers or aquifers, irrigate the surface naturally or via man-made wells.
The presence of water on the surface or underground is necessary and the local or regional management of this essential resource is strategic, but not sufficient to create such areas: continuous human work and know-how (a technical and social culture) are essential to maintain such ecosystems. [Wikipedia]