Misconceptions
First, let's clear up some common misconceptions. It is important to do this now so they don't interfere with your learning.
Chinese are communists.
Yes and no. The main political party is the Communist Party, and they control China. Communism was the political philosophy that Mao used to gain and keep control, and it is still technically the philosophy, but few Chinese are true communists. China gave up the idea of communism in the early 80s when Deng Xiaoping realized that the country could not progress economically under a system of state-controlled economy, so he said, "To get rich is glorious," thereby opening up the ability for people and companies to pursue profits. Even the 90+ million members are not really communists; they are party members in order to further their careers.
Taiwan is/is not part of China.
Mainland China - the Communists - continue to insist that Taiwan is a renegade province of China, and continue to insist that they will take it back by military force if necessary.
Unfortunately, many Chinese people hold on to this idea, fed by the never ending communist propaganda machine. [Author's opinion.]
Tibet is/is not part of China.
In 1953, the Chinese army invaded and annexed Tibet, guided in part by the questionable belief that Tibet was historically part of China, though more likely by the strategic need to control such a huge piece of real estate and buffer. Unfortunately, many Chinese people hold on to this idea, fed by the never ending communist propaganda machine. [Author's opinion.]
Since then, they have killed countless Tibetans, populated Tibet with Han Chinese, and persisted in eradicating Tibetan culture. They even control who can become a monk.