A sea is a unique body of salt water and an ocean is a sea of seas. For example, the Pacific Ocean seas include Coral Sea, South China Sea, Bering Sea, Okhotsk Sea, Arafura Sea, Sea of Japan, East China Sea and Yellow Sea.
The difference between the ocean and the sea is their size. Oceans are many times larger than seas, covering about seventy percent (70%) of the Earth's surface; while seas are sometimes small enough to be partly or wholly enclosed by land.
