'Tombolo' is a long narrow stretch of sand and/or shingle with one end attached to the mainland. It is a small island that has not been fully separated from the mainland. It is also referred to as tied islands because it seems too tethered to the coast. It is formed by wave diffraction and refraction. - A sand spit is a deposition bar off coast as it develops in places where long shore currents drift. This drift occurs due to waves meeting the beach at an oblique angle and moving sediments down in zigzag pattern. - A sand dune is a heaps or mounds of sand found in dry hot desert. It is most commonly in crescent shaped which are called Barchans. - A sand bar is found along the coast at a distance from the shoreline because of tidal currents that deposit rock debris. This results in the formation of landform which remains mostly submerged.