Nomadic people, (from the Greek: νομάδες, nomádes, "those who let pasture herds"), also known as nomads, are communities of people that move with herd animals from one place to another, rather than settling down in one location. There are an estimated 30-40 million nomads in the world. Many cultures have been traditionally nomadic, but traditional nomadic behavior is increasingly rare in industrialized countries. There are three kinds of nomads, hunter-gatherers moving between hunting grounds, pastoral nomads moving between pastures, and "peripatetic nomads" moving between customers.
Nomadic hunter-gatherers have by far the longest-lived subsistence method in human history, following seasonally available wild plants and game. Pastoralists raise herds and move with them so as not to deplete pasture beyond recovery in any one area. Peripatetic nomads are more common in industrialized nations, traveling from one territory to another and offering a trade wherever they go.