A hunter-gatherer or forager society is one in which most or all food is obtained from wild plants and animals, in contrast to agricultural societies which rely mainly on domesticated species. Hunter-gatherers are a type of nomad.
Hunting and gathering was the ancestral subsistence mode of Homo. As The Cambridge Encyclopedia of Hunter-Gatherers says: "Hunting and gathering was humanity's first and most successful adaptation, occupying at least 90 percent of human history. Until 12,000 years ago, all humans lived this way." Following the invention of agriculture hunter-gatherers have been displaced by farming or pastoralist groups in most parts of the world. Only a few contemporary societies are classified as hunter-gatherers, and many supplement, sometimes extensively, their foraging activity with farming and/or keeping animals.