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 language
The 7th (2016) edition of "Xiandai Hanyu Cidian", an authoritative one-volume dictionary on modern standard Chinese language as used in mainland China, has 13,000 head characters and defines 70,000 words.