Answer in brief.

What do you mean by hanging valley?

Erosion and deposition are also caused by the actions of glaciers. Glaciers are huge masses of snow that is transported, accumulated and deposited in other regions due to the action of natural agents. Hanging valleys are the result of erosional glacial action. It is because of the erosion of the main valley by the tributary glacier. It occurs when the main valley is broadened and extended by the erosion of the glacier. It leaves the other side of the main valley cut-off from its other side resulting in hanging valleys. It results in the formation of the raid and steep waterfalls.