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
The role of Chinese characters in Korean and Vietnamese is much more limited. At one time, many Chinese characters (called hanja) were introduced into Korean for their meaning, just as in Japanese. Today, Korean is written almost exclusively using the Hangul alphabet with a small number of Chinese characters. Each square block character contains Hangul symbols, or letters, that together represent a syllable. Similarly, the use of Chinese and Chinese-styled characters in the Vietnamese chữ nôm script has been almost entirely superseded by the Latin-based Vietnamese alphabet. Chinese characters are still actively used in South Korea today, mostly for signs, newspapers, books, and government documents.