Chinese characters are logograms used in the writing of Chinese and some other Asian languages. In Standard Chinese, and sometimes also in English, they are called hànzì (simplified Chinese: 汉字; traditional Chinese: 漢字).They have been adapted to write a number of other languages including: Japanese, where they are known as kanji, Korean, where they are known as hanja, and Vietnamese in a system known as chữ Nôm. Collectively, they are known as CJK characters. In English, they are sometimes called Han characters. Chinese characters constitute the oldest continuously used system of writing in the world. By virtue of their widespread current use in East Asia, and historic use throughout the Sinosphere, Chinese characters are among the most widely adopted writing systems in the world by number of users.