A river system consists of a main river and all its tributaries, which are smaller streams and rivers that flow into it. This network of waterways collects rainwater and runoff, transporting it across the landscape. River systems play a crucial role in shaping the environment, providing habitats for wildlife, and supporting ecosystems. The flow of water in a river system is influenced by factors such as terrain, climate, and human activities. Watersheds are areas of land that drain into a particular river, and they help manage water resources. Understanding river systems is essential for conservation and sustainable development.