The term Two Chinas refers to the current situation where two political entities each name themselves "China":

•  People's Republic of China (PRC), commonly known as "China", established in 1949, controlling mainland China and two special administrative regions, Hong Kong and Macau.
•  Republic of China (ROC) which controlled mainland China from its establishment in 1911/1912 to 1949. Since the end of 1949 when it lost control of mainland China in the Chinese Civil War, the ROC controls only Taiwan and some nearby island groups, and is now commonly known as "Taiwan".