hills
Hills are natural elevations that rise above the surrounding terrain, typically lower and less rugged than mountains. They often have rounded profiles and moderate slopes and occur in a wide range of landscapes, from plateaus to coastlines, upland plateaus to river valleys. Hills may form as isolated features or as elements of larger upland systems.
Hills originate through several processes. Tectonic uplift can raise blocks of crust, while weathering and erosion
Classification and human context: There is no universal height boundary between hills and mountains; regional usage