Nomads are known as a group of communities who travel from place to place for their livelihood.
4 features are :-
1) nomads are producers of food , and the size of their or ethnic units increases accordingly.
2) these groups raise livestock and they move about within their established territory to find good pastures for their animals.
3) they have to keep on moving from place to place and had to decide when and where to move , otherwise they along with their animals would starve .
4) they calculate their timing of movement so that green grasses and nutritious forage are available for their herds.
..........hope this will help u...........