Originally Posted by Mainad
It is separate from China proper for the historical reasons Mustard has explained but the Chinese government continues to regard Taiwan as officially part of China even though it has its own government. Taiwan also continues to regard itself as part of China. It just refuses to recognise the Communist regime in power there.
I should also point out that after their civil war defeat, the Kuomintang regime of Chiang Kai-shek saw themselves not only as Taiwan's rulers, but as the real rulers of China in exile with ambitions of one day returning to the mainland. The Chinese government of Mao Tse-tung saw Taiwan as a part of China, as have all Chinese governments since Mao's death in 1976.