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.
Written Chinese
For over two thousand years, the prevailing written standard was a vocabulary and syntax rooted in Chinese as spoken around the time of Confucius (about 500 BC), called Classical Chinese, or 文言文 "wényánwén". Over the centuries, Classical Chinese gradually acquired some of its grammar and character senses from the various dialects. This accretion was generally slow and minor; however, by the 20th century, Classical Chinese was distinctly different from any contemporary dialect, and had to be learned separately. Once learned, it was a common medium for communication between people speaking different dialects, many of which were mutually unintelligible by the end of the first millennium AD. A Mandarin speaker might say "yī", a Cantonese "yāt", a Shanghainese "iq", and a Hokkien "chit", but all four will understand the character <> to mean "one".