North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It can also be described as the northern subcontinent of a single continent, America. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Tectonic Plate, Greenland is included as part of North America geographically.