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 and transports water from various sources, such as rainfall and melting snow, across the landscape. The river system plays 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 like topography, climate, and human activities. Watersheds are the areas of land that drain into a particular river, and they help define the boundaries of a river system. Understanding river systems is essential for managing water resources and protecting the environment.