"Area that drains or contributes water to a particular point, stream, river, lake or ocean. Water- sheds are also referred to as basins. Watersheds range in size from a few acres for a small stream basin, to large areas of the country like the Chesapeake Bay Basin that includes parts of six states. (see river basin)" (Virginia Polytechnic Institute and State University, n.y.)
"Both river basins and watersheds are areas of land that drain to a particular water body, such as a lake, stream, river or estuary. In a river basin, all the water drains to a large river. The term watershed is used to describe a smaller area of land that drains to a smaller stream, lake or wetland. There are many smaller watersheds within a river basin"(Milwaukeeriverkeeper, n.d.).
Virginia Polytechnic Institute and State University. "A Glossary of Water-Related Terms", by Brian Benham. Publication 442-758
Milwaukeeriverkeeper. n.d. What's a River Basin Whats a Watershed? https://milwaukeeriverkeeper.org/whats-a-river-basin-whats-a-watershed/, last accessed 6 October 2021