A Special Administrative Region (SAR) (特別行政區) is a political subdivision of the People's Republic of China. The PRC at present has two SARs: Hong Kong and Macau where each has a Chief Executive as the head of their governments.
Article 31 of the Constitution of the People's Republic of China authorizes the National People's Congress to create special administration regions and to create a basic law which provides those regions with a large degree of internal autonomy, a separate political system and a capitalist economy under the principle of "One country, two systems" proposed by Deng Xiaoping.
The PRC has offered Taiwan a similar status to that of an SAR if it accepts mainland rule; however the Republic of China government refuses to accept the offer and only about 10% of the Taiwanese electorate support it.
The SARs of the PRC are empowered to conduct autonomous cultural and economic policies and as such are members of the WTO, even though they are not sovereign states, because they form their own customs areas and hence have their own international trade policies.