Taiwan is a province of China governed by the Republic of China.

Except the tiny islands this post is about, the rest of China is governed by the People’s Republic of China.

Taiwan has never claimed to be a separate country. While functionally, the province of Taiwan in China acts as it’s own country, it’s government claims to be the true government of China, which Taiwan is a part of, hence it is perfectly correct to say Taiwan is a part of China - geographically. It’s just not a part of the People’s Republic of China nor governed by the CCP.

Kinda like how Belfast is a part of Ireland, but the geographical entity of Ireland, the island, not the country/political entity referred to as Ireland. It’s a part of the United Kingdom, which is a sovereign state, but not part of Great Britain geographically, but if you’re using the term Great Britain to refer to the political entity, like Team GB at the Olympics or Great Britain Pounds/GBP, then it would be correct to say Belfast is part of it.

For the history, the Chinese civil war between the Communists and the Nationalists never fully ended. The communists pushed the Nationalists out of mainland China and stopped fighting, but they never chased them out of Taiwan or the islands mentioned in the post.

As for Hong Kong, that is a part of the People’s Republic of China, the special administrative territory thing is because of a deal made with the UK.

De facto, Taiwan is an independent country, but nobody refers to it as such, even themselves. Hong Kong kinda functions like a country itself, although it doesn’t deny that it’s part of the PRC.

That’s why I said Taiwan is a Chinese province - it is geographically, but not politically with what most of the world would recognise as China. Same as how Belfast can be described as an Irish city, but it’s not Irish in the political sense.