There is disagreement and confusion about what Taiwan is, and even what it should be called. Chiang Kai-shek's Republic of China (ROC) government, which fled the mainland to Taiwan in 1949, at first claimed to represent the whole of China, which it intended to re-occupy. It held China's seat on the United Nations Security Council and was recognised by many Western nations as the only Chinese government.
But in 1971, the UN switched diplomatic recognition to Beijing and the ROC government was forced out. Since then the number of countries that recognise the ROC government diplomatically has fallen to less than 30.
China regards Taiwan as a breakaway province which it has vowed to retake, by force if necessary. It says the ROC's lack of diplomatic recognition proves that the world agrees there is only one China.
But Taiwan's leaders say it is clearly much more than a province, arguing that it is a sovereign state. It has its own constitution, democratically-elected leaders, and 400,000 troops in its armed forces.
Given the huge divide between these two positions, most other countries seem happy to accept the current ambiguity, whereby Taiwan has most of the characteristics of an independent state, even if its legal status remains unclear.