A river source is the location where the river first starts to flow. Lakes, bogs, springs, streams, collections of snow or precipitation, glaciers, wetlands, and other rivers are examples of different origins.
River sources are often found at greater altitudes than the river’s downstream sections. A tributary is another name for a river or stream that enters a bigger river. The main course of the river frequently passes through a floodplain before coming to its mouth, where it discharges its water into a bigger body of water, like an ocean or a lake. The river’s source is located the furthest away from the estuary, which is also known as the river’s mouth.