A coast is a margin of land
where the land meets the sea
. It is area of varying width which includes the offshore
zones. The coastline
is the line where the land and sea meet -- the average tidal
line, whereas the coast itself includes the continental shelf and the coastal plains.
Other terms used to describe coastal areas include:
Shore - the area between low and high tide.
Beach - the accumulated loose sediments of sand, shell and rocks of the fore and backshore zones.
There are many different kinds of coasts (eg. sandy, rocky, cliffed, muddy). Most people prefer the sandy beach as it generally offers more to the user, like safer and cleaner swimming areas and soft, clean sand for sunbaking.
As mentioned before, the three zones of the beach system are the offshore, foreshore and backshore areas. The offshore extends from low tide out to a depth where wave action doesn't disturb the sediments on the sea floor. The foreshore the the area between the low and high tide levels. Finally, the backshore zone is above the high water mark and extends inland to wherever marine influences, eg. sea spray, still occur.