Do you know how a big factory makes lots of things like toys or clothes? Well, a very long time ago, there were 13 factories in China that were very important. These factories were called the "thirteen factories", which means there were 13 of them.
The people who owned these factories were from a country far away called Europe, and they wanted to trade things like tea and silk with the Chinese people. But the Chinese Emperor did not want them to come into the country and trade with the people.
So, the European people came up with an idea. They asked the Chinese Emperor if they could build their own factories in a special area called Guangzhou. The Emperor agreed to this but said that they could only trade with Chinese people that come to the factories.
So, the factories were built with big machines and lots of workers who made things like cloth and tea. The Chinese people came from all over the country to trade with the Europeans in the factories.
The products from the factories were now sold all over the world and this brought a lot of money and trade to China. It was a special time in history when the people from different parts of the world came together to trade and share their ideas. And that's what the thirteen factories were all about!