A drainage basin, also known as a watershed, is an area of land where all the water that falls as precipitation drains into a common outlet, such as a river, lake, or ocean. This area is defined by the topography of the land, with ridges or hills acting as boundaries that direct water flow. Drainage basins play a crucial role in the water cycle, collecting rainwater and snowmelt, which then flows into streams and rivers. They are essential for managing water resources, supporting ecosystems, and influencing local climates. Understanding drainage basins helps in environmental conservation and urban planning.