From the Wikipedia page [1]
Districts (Chinese: 區; pinyin: qū; Pe̍h-ōe-jī: ku) refer to a type of administrative division in Taiwan, an island controlled by the Republic of China.
After World War II, Taiwan, formerly under Japanese rule, was handed over to the Republic of China (see Retrocession Day). Consequently, several provincial cities were established in Taiwan, including Changhua, Chiayi, Hsinchu, Kaohsiung, Keelung, Pingtung, Taichung, Tainan and Taipei. On the other hand, the towns (Japanese: 町) in the original prefecture-controlled cities were merged into several districts. However Changhua and Pingtung were downgraded to county-controlled cities and their districts are now defunct.
When Taipei was promoted as a special municipality by the central government in 1967, several townships surrounding the city were merged into Taipei City and were reorganized as its districts. Afterwards, through another reorganization in 1990, the 12 current districts were formed. In addition, Kaohsiung, the largest city in southern Taiwan, was promoted as a special municipality in 1979. Siaogang Township was also merged to Siaogang District.
In December 2010, the four new special municipalities were established namely Kaohsiung, New Taipei, Taichung, and Tainan. Subsequently, all the county-controlled cities and townships in Kaohsiung, Taichung, Tainan, and Taipei Counties were reformed as districts of the new Kaohsiung, Taichung, Tainan, and New Taipei cities respectively. Their names, nevertheless, remained the same. The same thing happened to Taoyuan on 25 December 2014 where there are additional new 13 districts from the former county.
These municipalities and provincial cities use district administrative centers for public affairs services to serve the residents of these districts. Also, the directors of these districts and administrative centers are appointed by the mayors, with four years per term.
On 4 February 2014, six districts were reclassified as Special Municipal Mountain Indigenous District (Chinese: 直轄市山地原住民區; pinyin: Zhíxiáshì Shāndì Yuánzhùmín Qū; or shortened as Mountain Indigenous District (山地原住民區; Shāndì Yuánzhùmín Qū)): Wulai in New Taipei, Fuxing in Taoyuan, Heping in Taichung, along with Namasia, Maolin, and Taoyuan in Kaohsiung.