Stream of freshwater that travels from mountains in a fixed channel or a stream bed to finally meet an ocean or a lake is termed as a river. The origins of this stream of fresh water are the mountains. The snow above the mountain peaks melt and get transformed into large streams and springs. Among these streams the larger ones are called rivers and the smaller ones are known as either creeks, brooks, rivulets or tributaries. The Earth's gravitational force is responsible for the flow and direction of rivers. The main sources of water in a river are the melting glaciers, ground water and rainwater.

Rivers play an important role in the water cycle. During heavy rains in the hills, the water from the slopes of the hills dribbles down and flows onto a riverbed. In the beginning, when the water travels down, it is uniformly distributed and is called surface run off. After traveling some distance it starts flowing in parallel fashion which moves with a greater velocity. After traveling certain distance, very soon, this water, moving in a parallel fashion, begins to combine and gets transformed into streams. When these streams converge they give rises to brook. The brook flows through the valley. The brook gradually becomes constant because of inclusion of groundwater. Finally, these brooks get transformed into steady flowing rivers once the water in the brooks gains volume.

The rivers are of different types. The classification of river into all these types is made as per the amount of sediments it carries along with it. Accordingly, the different types of rivers are Youthful River, Mature River and Old River.

Kum Martin is an online leading expert in education. He also offers top quality articles like:
Early Chinese Astronomy, Types Of Archaeology http://greaterlearning.org/archaeology/index.html.