Meanders are winding curves or bends in a river or stream. They form as water flows over land, eroding the outer banks and depositing sediment on the inner banks. This process creates a serpentine shape, allowing the river to navigate around obstacles and changes in the landscape. Over time, meanders can become more pronounced, leading to the formation of oxbow lakes when a river cuts off a bend. These features are important for ecosystems, as they create diverse habitats for various plants and animals, contributing to the overall health of the river environment.