Coastline is the boundary where land meets the ocean or sea. It can include features such as beaches, cliffs, bays, and estuaries. Coastlines can be straight or irregular, with many shapes and patterns. Waves and tides often affect the shoreline.

Coastlines are found along continents and islands around the world. They change over time due to natural processes such as erosion and sediment movement. Coastlines are used by humans for settlement, travel, and fishing. They are also home to many plants and animals.