In geography, an oasis is an isolated place in the desert where there is vegetation. Most often, this occurs around a source of water. Oases provide a habitat for animals and are used as a source of water for humans.
The knowledge of the location of oases has been important for trade and transportation routes in desert areas. Caravans must travel via oases so that supplies of water and food can be refilled. Thus, political or military control of an oasis has in many cases meant control of trade on a particular route. For example, the oases of Awjila, Ghadames and Kufra, in modern-day Libya, have at various times been vital to both North-South and East-West trade in the Sahara desert. The word oasis came into English via Greek ὄασις , which was borrowed from Egyptian wḥ3t or Demotic wḥỉ. It was not borrowed from Coptic ouaḥe (*/waħe/), as is sometimes suggested; the Greek word is attested several centuries before Coptic existed as a written language.