<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> An ocean (from Ancient Greek Ὠκεανός, transc . Okeanós, the sea of classical antiquity) is a body of saline water that composes much of a planet's hydrosphere . On Earth, an ocean is one of the major conventional divisions of the World Ocean . These are, in descending order by area, the Pacific, Atlantic, Indian, Southern (Antarctic), and Arctic Oceans . The word sea is often used interchangeably with "ocean" in American English but, strictly speaking, a sea is a body of saline water (generally a division of the world ocean) partly or fully enclosed by land . </P> <P> Saline water covers approximately 360,000,000 km (140,000,000 sq mi) and is customarily divided into several principal oceans and smaller seas, with the ocean covering approximately 71% of Earth's surface and 90% of the Earth's biosphere . The ocean contains 97% of Earth's water, and oceanographers have stated that less than 5% of the World Ocean has been explored . The total volume is approximately 1.35 billion cubic kilometers (320 million cu mi) with an average depth of nearly 3,700 meters (12,100 ft). </P>

What type of water is in the ocean