Sea

A sea is a large body of salt water. The term applies both to the interconnected global ocean system and to a named body of water, usually a marginal sea partly enclosed by land or a large, nearly landlocked body of water. There is no sharp scientific boundary between a sea and an ocean, though seas are generally smaller and more often bounded by land; the Sargasso Sea is a notable exception, having no coastline at all despite its name. Seas hold the great majority of Earth's water and cover about 71 percent of the planet's surface, and their evolutionary history is foundational, since many of the major groups of living organisms are thought to have first evolved there.