What feature is created when a river erodes downwards, resulting in a 'V' shaped valley?

The feature created when a river erodes downwards, resulting in a 'V' shaped valley, occurs in the upper course of the river. In this stage, the river primarily down-cuts into the landscape, which leads to the formation of steep valleys characterized by their 'V' shape. This process is driven by the high energy of the river as it flows over steeper gradients, allowing it to exert greater force on the riverbed and banks.

During the upper course, the river is often fast-flowing and includes features such as Rapids and Waterfalls due to the steep terrain. As erosion deepens the channel, it creates the distinct 'V' shape as the sides of the valley erode more slowly compared to the downward cutting of the riverbed. This is in contrast to the middle and lower courses of a river, where lateral erosion predominates and valleys tend to be wider and flatter, and deltas, which are formed where a river meets a body of water and sediments are deposited, occur at the river's mouth rather than upstream.