Which terrain feature is classified as a depression?

A valley is classified as a depression because it is an elongated low area that is typically situated between hills or mountains. Valleys often form through processes such as erosion from rivers or glaciers and are characterized by lower elevations compared to the surrounding terrain. This distinguishes them from hills and ridges, which are both elevated features, and from saddles, which are not considered depressions in the same context. Saddles represent a dip between two higher points, while valleys are broader, encompassing a larger area of lower elevation. Understanding these definitions is essential for interpreting topographic maps and effectively navigating various terrains during military operations.