A U-shaped valley is a type of valley characterized by its distinct U shape, formed primarily by the erosion of glaciers. As glaciers move through mountainous regions, they carve out the landscape, creating steep sides and a flat bottom. This process results in the valley's wide, open appearance, which contrasts with the V-shaped valleys formed by river erosion. These valleys are commonly found in areas that have experienced glaciation, such as the Alps and Rocky Mountains. U-shaped valleys often contain features like hanging valleys and glacial lakes, showcasing the powerful impact of glacial activity on the Earth's surface.