What is a topographic high that separates drainage basins?

A topographic high that separates drainage basins is known as a watershed or divide. It is typically a ridge or elevated area where water on one side flows into one drainage basin, while water on the other side flows into a different basin. This geographic feature plays a crucial role in hydrology, influencing water flow and ecosystem dynamics within the respective basins. Watersheds can vary in size, from small hills to large mountain ranges.