River

A river is a natural watercourse, usually freshwater, flowing toward the ocean, a lake, a sea or river to another. In some cases, just a river flows into the soil or dry completely before reaching another body of water. small rivers can also be called by various names, including brook, stream, creek, stream, tributary and creek, there is no general rule that defines what can be called a river, although in some countries or communities in a stream can defined by their size. Many names for small rivers are specific to geographic location, an example is "burn" in Scotland and northeast England. Sometimes a river is said to be larger than a creek, but not always so, because of the vagueness of language. 

A river is part of the hydrological cycle. Water in a river is generally collected from precipitation through surface runoff, groundwater recharge, springs, and release of water stored in natural ice and snow accumulation (eg, glaciers). Potamology is the scientific study of rivers.