* Erosion is the process of wearing away and transporting material. Think of waves crashing on a beach, carrying away sand grains.

* Deposition is the process of dropping or settling that transported material.

How sandbars form:

1. Waves and currents: Ocean waves and currents carry sand along the shoreline.

2. Energy decrease: When the waves or currents lose energy, they can no longer carry the sand as easily.

3. Deposition: The sand is deposited in areas where the energy is lower, such as the calmer waters between the shore and a headland, forming a sandbar.

In short, sandbars are formed by the deposition of sand by moving water, not by the erosion of existing landforms.