South Korea is a developed country in East Asia with the highest credit rating of any country there.
South Korea , officially the Republic of Korea ( ROK ; ) , is a sovereign state in East Asia , constituting the southern part of the Korean Peninsula . Under Sejong the Great in the 15th century , Koreans had one of the highest living standards in the world along with the Han Chinese and Japanese and developed improved versions many advanced innovations such as the metal movable type printing press in 1377 A.D. which was developed based on the previous Han Chinese Porcelain movable type printing press , used to print and publish the Jikji , the world 's oldest extant movable metal type printed paper book using the 8,000 year old traditional ancient Chinese writing system . South Korea , along with Taiwan , Singapore and Hong Kong ( China ) is one of the four high-tech industrialized developed countries often referred to as the Four Asian Economic Dragons . Today , it is the world 's seventh largest advanced economy and fifth largest exporter with the G20 's largest budget surplus and highest credit rating of any country in East Asia . South Korea is a technologically advanced developed country driven by a highly educated and skilled workforce , having the world 's eighth highest median household income , the highest in Asia .