While the seas of the world are technically all connected into one global ocean, they are commonly divided geographically into five main oceans. These are the Atlantic, Pacific, Indian, Arctic and Antarctic Oceans.
The number of oceans, or seas, in the world is a matter of classification. Some geographers divide the Pacific into the North Pacific and the South Pacific and the Atlantic into the North Atlantic and the South Atlantic using the equator as a theoretical dividing line. For that reason, the Earth is often said to have seven seas. There are also many smaller bodies of water called seas. Some, like the Mediterranean Sea and the Red Sea, are large geographically distinct inlets of ocean water. Others, like the Sargasso Sea, aren't separate from the main oceans at all, but have acquired a unique name because of some distinctive feature.