The coast is the area where the land and sea meet. This results in a special set of environments where the marine and terrestrial areas influence each other. The term 'coastline' is normally used to refer to the narrow strip around the country where land and coastal waters come into direct contact.
Coastal environments are among the most complex regions of the world's oceans. They are the transition zone between the open ocean and terrestrial watersheds with important and disparate spatial and temporal scales occurring in the physical as well as biogeochemical processes.
Coastal areas are commonly defined as the interface or transition areas between land and sea, including large inland lakes. Coastal areas are diverse in function and form, dynamic and do not lend themselves well to definition by strict spatial boundaries.