A coastline is the area where land meets the ocean or sea. It can vary greatly in shape and size, featuring sandy beaches, rocky cliffs, or marshy wetlands. Coastlines are important for ecosystems, providing habitats for various plants and animals, and they often serve as recreational areas for people. Coastlines are also influenced by natural processes such as erosion and sediment deposition. Human activities, like construction and tourism, can impact these areas, leading to changes in their structure and health. Understanding coastlines is essential for environmental conservation and sustainable development, especially in regions affected by climate change and rising sea levels.