Basin is a low area of land where water collects. It can be surrounded by higher land that directs water into it. Basins may hold rivers, lakes, or underground water. Some basins are large regions, while others are smaller and more local.

Basins are found worldwide on land and under oceans, such as river basins and ocean basins. They formed over long periods through Earth processes. Basins can include ecosystems and water systems. Many plants, animals, and human communities exist in these areas.