Hunminjeongum, the language system made by King Sejong in Chosun dynasty, was composed of 28 words in the year 1446 when it was first created, but currently only 24 words are used and it is called Hangul. Hangul means big words in that the word Han from Hangul means big. Hangul is the only language that the creator, the date of promulgation, and the principle of creation are known. The book that explains the principle and instructions of Hangul is one of the UNESCO registered treasures.