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 alphabet
There are and have been several Chinese alphabets, that is pre-existing alphabets adapted to write down the Chinese language. However, the standard Chinese writing system uses a non-alphabetic script with an alphabet for supplementary use. There is no original alphabet native to China. China has its Pinyin system though sometimes the term is used anyway to refer to logographic Chinese characters ("sinograms"). It is more appropriately used, though, for phonemic transcriptions such as pinyin.