Coastline

...Because the area inland from the high tide line is also affected by waves, especially those during storms, the area between the low tide line and the land limit affected by waves is called the sea shore or simply the shore. The beach is divided into the foreshore (between the low tide line and the high tide line) and the backshore (landward of the high tide line), and the landward limit of the backshore is called the shore line or coastline in a broad sense. The coast can refer specifically to the land (seashore) on the sea side of the coastline (broad sense), or it can refer broadly to the land affected by the action of the sea, such as the beach and the sea cliffs, sand dunes, lagoons, and wetlands behind it.

*Some of the terminology that mentions "coastline" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…高潮線より内陸側も波浪，とくに暴風時の波浪によって影響を受けるので，低潮線と波浪の作用の及ぶ陸の限界の間を海浜sea shoreまたは単に浜shoreとよぶ。海浜は前浜(低潮線と高潮線の間)と後浜(高潮線より陸側)に区分され，後浜の陸側の限界を広義の海岸線shore lineまたは沿岸線coastlineとよぶ。海岸は，海岸線(広義)より海側の陸地(海浜)を限定して指す場合と，海浜とその背後の海食崖，砂丘，潟，湿地など，海の作用が影響する陸地を広く指す場合とがある。…

※「coastline」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報