CJK Unified Ideographs is a Unicode block containing the most common CJK ideographs used in modern Chinese and Japanese.
The Chinese, Japanese and Korean (CJK) scripts share a common background. In the process called Han unification the common (shared) characters were identified, and named «CJK Unified Ideographs». Unicode defines a total of 74,617 CJK Unified Ideographs. The terms ideographs or ideograms may be misleading, since the Chinese script is not strictly a picture writing system. Historically, Vietnam used Chinese ideographs too, so sometimes the abbreviation «CJKV» is used. This system was replaced by the Latin-based Vietnamese alphabet in the 1920s.