What is a Sea?

 
A division of an ocean or large bdy of water partly enclosed by land.
 

What is an Example of a Sea?

 
The North Sea, an arm of the Atlantic Ocean, occupies an area of about 222,000 square miles and a length of about 400 miles. It extends south from the Norwegian Sea between Norway and the British Isles. The North Sea is known for its excellent fishing and extensive oil and natural gas deposits.