Ocean, ocean, whether spoken or written, these two words are always inseparable. In fact, except for a few inland seas, the sea and the ocean are indeed interconnected bodies of water, but they are not the same thing. Geographers divide the seas and oceans based on their connection to land.
According to this division, the ocean is huge, open, and is the main body of the ocean. There are five oceans in the world, each of which has its own ocean currents and tides, and is less affected by land. The ocean is very deep, mostly above 3000 meters. The water in the ocean is pure and has little impurities, always blue, and never needs to find an outlet for itself.
The sea is adjacent to land and is partially or mostly surrounded by land. The sea is much smaller in area than the ocean. For example, the largest Mediterranean Sea is much smaller in area than the smallest Arctic Ocean. The sea does not have its own tides. The temperature, salinity, color and impurity content of the sea water are greatly affected by rivers, climate and pollution on land. For example, in Alaska's Cook Bay, due to the integration of glaciers, the sea water is milky gray, and the water temperature and salinity are very low. In the East China Sea of China, the coastal water turns yellow due to the Yangtze River carrying a large amount of sediment into it. In addition, the sea is much shallower than the ocean.
There are nearly 50 seas in the world, such as the Mediterranean Sea, the Bering Sea, the Caribbean Sea, etc. They are either marginal seas or intercontinental seas.