Seas are the waters of the Earth surrounding the continents and all are connected to each other. As opposed to the seas, lakes and rivers on land are called inland waters. Three quarters of waters and seas cover the Earth’s surface, and only barely a quarter is actually dry land. In that sense, our planet should rather be called Ocean!
This would be apt, as it is exactly the oceans that set the Earth apart from other planets in the solar system. Seen from outer space, we live on a blue planet. 97 percent (1370 million cubic kilometers) of the Earth’s waters are contained in the oceans, and only about 2 % is in the ice sheet of Greenland and Antarctica. The small remaining percentage includes lakes and rivers, and also the water content of the atmosphere.