What does river mean?

River is a natural watercourse, usually freshwater, that flows downhill from higher ground to a lower level, such as a lake, sea, or ocean. The term "river" can also refer to an artificial watercourse, such as a canal. Rivers are fed by rainfall, snowmelt, or groundwater. They play an important role in the water cycle, as they transport water from one place to another. Rivers also provide water for drinking, irrigation, and transportation. They are also important habitats for plants and animals.