Bopomofo or Zhuyin was named Bopomofo based on the first four glyphs in its syllabary. It was originally developed for the government of the Republic of China for use as a phonetic script, however, when pinyin (a Latin-based phonetic script) was created, the People's Republic of China (PRC) moved away from Bopomofo.
People living on the island of Taiwan (Republic of China) continues to use Bopomofo for inputting Han characters in all forms of media and text input on keyboards and smart devices. The use of Bopomofo is most commonly associated with media oriented towards children or foreign language materials.