zh

zh is the ISO 639-1 two-letter code used to designate the Chinese language in cataloging, linguistics, computing, and international standards. It is commonly employed as a language tag in software, websites, and data formats to indicate Chinese content, sometimes paired with regional or script variants such as zh-CN or zh-TW.

The label Chinese refers to a family of related languages within the Sino-Tibetan language group. The most widely spoken member is Mandarin, which serves as the basis for Standard Chinese. Other major varieties include Wu, Cantonese, Hakka, and Min, among many others. These varieties display substantial phonological and lexical differences, with varying degrees of mutual intelligibility.

Written Chinese uses logographic characters and can be produced in two main writing systems: Simplified Chinese characters and Traditional Chinese characters. Simplified characters are officially used in Mainland China and Singapore, while Traditional characters are used in Taiwan, Hong Kong, and Macau. In addition to characters, there are romanization schemes such as Pinyin that aid pronunciation and literacy but are secondary to the Chinese writing systems.

In digital and language-tag contexts, zh is often expanded with script and regional subtags. Examples include zh-Hans for Simplified Chinese and zh-Hant for Traditional Chinese, with regional codes like zh-CN (Mainland China), zh-TW (Taiwan), and zh-HK (Hong Kong). These variants reflect differences in script usage and regional standards while representing related linguistic systems.