structural:scholar_edition, structural:summarization
Naval warfare is combat in and on the sea, the ocean, or any other battlespace involving a major body of water such as a large lake or wide river.

The armed forces branch designated for naval warfare is a navy. Naval operations can be broadly divided into riverine/littoral applications (brown-water navy), open-ocean applications (blue-water navy), between riverine/littoral and open-ocean applications (green-water navy), although these distinctions are more about strategic scope than tactical or operational division. The strategic offensive purpose of naval warfare is projection of force by water, and its strategic defensive purpose is to challenge the similar projection of force by enemies.