The ocean is a large body of sea water connected together. and covers approximately three-quarters (71%) of the earth's surface. The oceans are arranged in descending order of size: pacific ocean atlantic ocean Indian Ocean, Southern Ocean, and Arctic Ocean The word sea is sometimes used interchangeably with "ocean" or "ocean" in American English. But if we speak specifically, sea is a source of salty water. (part of the ocean) the part that has land next to it