How is the formation of a sandbar different from from the changes to a beach caused by water erosion?

The formation of a sandbar occurs when sediment is deposited by water currents, creating a submerged or partially exposed landform in shallow areas, often offshore. In contrast, changes to a beach caused by water erosion involve the removal of sand and sediment from the shoreline due to wave action, leading to a retreat of the beach. While sandbars are formed through deposition, beach erosion results in the loss of land, showcasing contrasting processes of sediment dynamics. Both processes, however, are influenced by the movement and energy of water.