deserts come in all shapes and forms.Technically,a deserts is defined as a very dry piece of land.Deserts receive less than 250 mm of rainfall each year.most people imagine deserts as full of sand,but in fact,many deserts are not full of massive sand dunes.Mountain ranges,gravel plains,salt flats,and rock beds characterize most deserts.Many desert are formed because tall mountains block precipitation.
There are four major types of deserts:hot and dry