Han kuen is the name of a character called the Korea fiction represents a Hanja. It refers to the Hanja Chinese characters that are used in Korea prior to the invention of the alphabet, use instead.
Hangul is the name of the Korean alphabet was invented to replace the Hanja. Hanja means the Chinese characters used in Korean before the invention of the alphabet instead.
Hangul name call letters of the Korean alphabet was invented ฮันจา instead. ฮันจา means that the Chinese characters used in Korean before the invention more literal representations.