The South China Sea is a marginal sea that is part of the Pacific Ocean, encompassing an area from the Singapore and Malacca Straits to the Strait of Taiwan of around 3,500,000 square kilometres (1,400,000 sq mi). The area's importance largely results from one-third of the world's shipping transiting through its waters, and that it is believed to hold huge oil and gas reserves beneath its seabed. 

It is located：

south of mainland China, including the island of Taiwan, in the east;
east of Vietnam and Cambodia;
west of the Philippines;
east of the Malay peninsula and Sumatra, up to the Strait of Malacca in the west; and
north of the Bangka–Belitung Islands and Borneo

The minute South China Sea Islands, collectively an archipelago, number in the hundreds. The sea and its mostly uninhabited islands are subject to competing claims of sovereignty by several countries. These claims are also reflected in the variety of names used for the islands and the sea.