List of Ocean
An ocean, is a body of saline water that composes a large part of a planet's hydrosphere.
In the context of Earth, it refers to one or all of the major divisions of the planets World Ocean.
They are, in descending order of area:
The word "sea" is often used interchangeably with "ocean", but strictly speaking a sea is a body of saline water (possibly a division of the World Ocean) partly or fully enclosed by land.