Erosion happens more quickly on bare rocks. Weathering is part of the process it weakened by the weathering such as frost, sunshine, and rain. Rocks can be eroded by weathering through heat, cold, and frost, and chemical weathering. Erosion may move by mass movement of rock and soil.
the waves erode the bace of cliffs, undermining them and making them collapse. This can create coastal features. Erosion happens faster when shingle is thrown against the cliffs by the waves.
mountain ranges contain deep valleys that have been carved out by glaciers. A glacier is like a snow moving river of ice that flows downhill, carried forwards by its huge weight.