A stream bed is the channel or area where a stream flows. It consists of the ground and materials, such as rocks and soil, that shape the path of the water. The stream bed can vary in width and depth, depending on the amount of water and the surrounding landscape. Stream beds play a crucial role in the ecosystem by providing habitats for various plants and animals. They help filter water, reduce erosion, and support the natural flow of water. Understanding stream beds is important for maintaining healthy rivers and wetlands.