In any standard dictionary the meaning of dune is that of a small hill made of sand and which is why the more common use of the term is 'sand dune' itself. You can find sand dunes in deserts, near the sea and sometimes they can be found in the beds of rivers and sea also.
Most of the times the different sizes of dunes are decided by the interaction of dunes with the blowing wind as it is wind that collects sand to form a dune. Dunes play a strategic role in the geographical process also; they save the coastal land from the process of erosion as the storm waves coming from the sea can play spoilsport for this land and dunes work as a protecting wall.
Most of the times the different sizes of dunes are decided by the interaction of dunes with the blowing wind as it is wind that collects sand to form a dune. Dunes play a strategic role in the geographical process also; they save the coastal land from the process of erosion as the storm waves coming from the sea can play spoilsport for this land and dunes work as a protecting wall.