CJK characters
Chinese is written almost exclusively in Chinese characters. It requires over 3,000 characters for general literacy, but up to 40,000 characters for reasonably complete coverage. Japanese uses fewer characters — general literacy in Japanese can be expected with 1,945 characters. The use of Chinese characters in Korea is becoming increasingly rare, although idiosyncratic use of Chinese characters in proper names requires knowledge (and therefore availability) of many more characters. However, even today, students in South Korea are taught 1,800 characters.
Chinese characters
The traditional six-fold classification ("" / "six writings") was first described by the scholar Xu Shen in the postface of his dictionary "Shuowen Jiezi" in 100 AD.
While this analysis is sometimes problematic and arguably fails to reflect the complete nature of the Chinese writing system, it has been perpetuated by its long history and pervasive use.