The document discusses several key topics regarding coastal processes and geomorphology: 1) Coasts are important interfaces between land and sea that are hazardous due to erosion and flooding. They also provide economic value through activities like tourism. 2) Coasts are open systems with inputs of energy, sediments, and processes like erosion and deposition that create landforms. They have outputs like deposited material onshore. 3) Sediment cells define discrete lengths of coastline where sediment movement is self-contained through longshore drift. These inform shoreline management plans.