Okay, kiddo, so you know how every country has its own states or provinces, right? Just like how America has California and New York, and Canada has Ontario and Quebec. Well, China is a big country and it also has many states or provinces.
One of these provinces is called Xinjiang, which is in the far west of China. A long time ago, back in the olden days, Xinjiang was its own separate place with its own people, language, and culture. But then, a few decades ago, Xinjiang became part of China officially.
Now, this wasn't just a simple thing like two friends deciding to shake hands and become buddies. There were some complicated things going on that made some people very happy and others very unhappy.
See, Xinjiang is a special place because the people who live there are mostly not the same as the people who live in the rest of China. They have their own language and culture, and they mostly follow a religion called Islam. The people who run China, however, are mostly not these kinds of people. They speak a different language and follow a different religion or no religion.
So some people from Xinjiang didn't like being part of China because they didn't feel like they were being treated fairly. They thought that China was trying to force them to be like everyone else in China and not let them be themselves.
However, the people who run China wanted Xinjiang to be part of China because they saw it as an important piece of land that they wanted to control. They thought that if Xinjiang was part of China, then they would have a better chance of keeping it safe and making sure that other countries didn't try to take it away.
So there were a lot of arguments and fights about whether or not Xinjiang should be part of China. Eventually, the people who run China won and they made Xinjiang become part of China officially.
Nowadays, there are still arguments and fights about this because some people from Xinjiang still don't like being part of China and they want to be their own separate place again. But for now, Xinjiang is officially part of China and its people have to follow the laws and rules set by the Chinese government.