A prairie is a stretch of open, relatively flat land covered in grasses, herbs, and small shrubs, without any trees present. Many people think of Central North America when they hear the word prairie, although similar plains exist in places like Russia and South America as well. The prairie is a unique ecosystem, supporting plants and wildlife which are not found in other environments. Humans have contributed immensely to the shape of the world's prairies for thousands of years.

The word is taken directly from the French word for “meadow,” and it was first used to describe the high grasslands of Central North America in 1773. The concept of the prairie was completely alien to European explorers, who were not accustomed to the sight of tall grasses waving to the horizon. Many of the animals of the prairie were also unusual and unexpected, and these explorers recognized that the flatland was a unique environment.

Gentle slopes and large flat areas are the hallmark of a prairie, which has a mixture of grasses which may grow as high as a person's head. Wildflowers and aromatic herbs are usually abundantly distributed throughout the prairie, and small shrubs may be found in some regions as well. Numerous animals call the tall grasses of the prairie home, while others burrow into the soil for shelter. The prairie also hosts unique birds such as larks.

Larger animals have also historically depended on the prairie. In the Americas, the buffalo is probably the best known example of a large animal species which was once abundantly distributed across the prairie lands. These animals helped to churn and fertilize the soil as they wandered, scattering seeds across the prairie with their hooves. The rich soil of the plains turned out to be highly beneficial for humans settling in the prairie, since they could establish large farms which supported both animals and crops.

Although prairies appear to be totally natural features, archaeologists believe that they may have been heavily influenced by animals and people, who contributed to the prairie ecology over thousands of years of farming, hunting, and roaming. The unique conditions in the prairie were probably created through a combination of feeding animals, deliberate early human shaping, and factors of nature and geology. Some biologists are concerned about the health of the prairie, as the land has been heavily exploited for farming and industrial use. They fear that the disappearance of the prairie would be a great loss for mankind, as it represents such an interesting and unique ecology.