How many Chinas are there?
Depending upon who you ask you will find that the answer is two: the People's Republic of China, aka the China we all think of, and the Republic of China, perhaps better known as Taiwan.
The reason being for this is that originally the Republic of China (ROC) was a government that covered all of China and its territories, including the island of Taiwan. Though after the communist uprising and the ensuing Chinese Civil War (1927 - 1936 and 1945 - 1950) the ROC was driven out of the mainland, forcing it to take refuge on the island of Taiwan were it continued to claim to be the true government of China, despite the establishment on mainland China of the People's Republic of China (PRC).
The result of this being that both the ROC and the PRC claim to be the legitimate government of all of China, leading to there being two Chinas.
Though in order to avoid confusion Taiwan is used for the ROC island nation.
It should also be noted that the Chinese aren't to fond of people mentioning Taiwan as the other China.
So ladies and gentlemen I give you the ultimate petty fight.
Further Info: https://en.m.wikipedia.org/wiki/Chinese_Civil_War