Shoreline indentation is a term used to describe the shape of a coastline. It can refer to bays, coves, inlets, and rias, all of which are indentations in the shoreline. Bays are large bodies of water surrounded by land on three sides, while coves are smaller and more sheltered than bays. Inlets are narrow bodies of water that connect two larger bodies of water, and rias are long, deep inlets created by rivers. All of these indentations in the shoreline create a unique and varied landscape.