South Korea, officially the Republic of Korea, is a country in East Asia, constituting the southern part of the Korean Peninsula. The name Korea is derived from Goryeo, a dynasty which ruled in the Middle Ages. It shares land borders with North Korea to the north, and oversea borders with China to the west and Japan to the east. South Korea lies in the north temperate zone with a predominantly mountainous terrain. Roughly half of the country's 50 million people reside in the metropolitan area surrounding its capital, the Seoul Capital Area, which is the second largest in the world with over 25 million residents.
The won is the currency of South Korea. A single won is divided into 100 jeon, the monetary subunit. The jeon is no longer used for everyday transactions, and appears only in foreign exchange rates.
The old "won" was a cognate of the Chinese yuan and Japanese yen. It is derived from the Hanja, itself a cognate of the Chinese character (yuan) which means "round shape." The won was subdivided into 100 jeon, itself a cognate of the Chinese character (qian) which means "money" and also used as a unit of money in the ancient times. The current won (1962 to present) is written in hangul only.