The Sargasso Sea

Imagen: "Sargasso sea", US Fish and Wildlife Service, (2006) Wikimedia commons.
Instructions: Read the text. Look at the underlined words.
Can you explain me about the Sargasso Sea?
I can. The Sargasso Sea is a region of the North Atlantic Ocean bounded by four currents, that together form a circulating ocean stream called a gyre. It is the only such oceanic region on Earth to which the term sea has been extended, all others being bound entirely or mostly by land. A distinctive body of water often found with its characteristic brown Sargassum seaweed and often calm blue water, it is very different from the rest of the Atlantic Ocean.
Sargasso Sea. Retrieved and adapted April, 2017 from https://en.wikipedia.org/wiki/Sargasso_Sea