About Korean
Korean is the official language of Korea, both South and North. It is also one of the two official languages in the Yanbian Korean Autonomous Prefecture in China. There are about 78 million Korean speakers worldwide. In the 15th century a national writing system was commissioned by Sejong the Great, the system being currently called Hangul. Prior to the development of Hangul, Koreans used Hanja (Chinese characters) to write for over a millennium.

Korean is spoken by the Korean people in North Korea and South Korea and by the Korean diaspora in many countries including the People's Republic of China, Japan, and the United States. Korean-speaking minorities exist in these states, but because of cultural assimilation into host countries, not all ethnic Korean immigrants may speak it with native fluency.

source: Korean