What is the difference between an ocean and a sea?
Answer: Basically, a sea refers either to a smaller division of the oceans or to a large saltwater bay partially enclosed by land. There are many seas in the world; the principal ones are [in order of size]: South China, Caribbean, Mediterranean, Bering , Gulf of Mexico, Sea of Okhotsk, East China, Hudson Bay, Sea of Japan, North Sea, and the Baltic Sea.
How did the Yellow, Red, and Black Seas get their names?
The Yellow Sea is named for the yellow silt deposited by the Yellow River in its waters; the Red Seas gets its name from the masses of reddish seaweed found in its waters; the Black Sea is quite dark and stormy, thus the name Black Sea.