How is the foreshore of a beach different from its backshore?

The beach profile is divided into two primary zones based on their relationship to tidal activity and wave energy.1

The Foreshore

The foreshore is the seaward portion of the beach, extending from the low-tide line to the high-tide mark. It is essentially the intertidal zone, characterized by a relatively steep slope where waves break and surge. Because it is subjected to constant wave action, the foreshore is a zone of continual change; its shape and sediment composition can shift daily depending on energy conditions. During low-energy periods, the foreshore tends to be steeper, while storm conditions often result in a gentler slope due to erosion.1

The Backshore

The backshore is the landward, nearly horizontal section of the beach located above the high-tide level. Unlike the foreshore, it is in the supra-tidal zone and is generally not reached by regular astronomical tides. It remains relatively inactive during non-storm conditions, though wind may transport sediment to form dunes. The backshore is only subjected to wave activity during severe storm events, which may deposit features such as berms or cause significant erosion.213