What is the term for where a river begins?

The term for where a river begins is referred to as the source. The source is the starting point of a river, typically found in higher elevations such as mountains or hills, where rainwater or melting snow collects and flows downwards, eventually forming a river. Understanding this concept is important in mapping river systems and analyzing water flow within different landscapes.

In contrast, a confluence is the point where two rivers meet, while the mouth is the point where a river flows into a larger body of water, such as a lake, sea, or ocean. The drainage basin, also known as a watershed, is the area of land from which rainfall drains into a particular river or lake, encompassing its entire catchment area. Each of these terms describes different aspects of a river system, but the source specifically indicates the origin of the river itself.