Kyakhta trade was a very important form of trade that happened a long time ago between Russia and China, when both countries had emperors who ruled over them. The trade happened mostly in the 18th century, which is a really, really long time ago.
At that time, Russia and China were neighboring countries and they wanted to trade with each other, which means they wanted to exchange things that they made or had for things that the other country made or had. Russia had things like furs, which are the soft and fluffy skin of animals that people wear to keep warm, and China had things like silk, which is a very, very soft and beautiful fabric that people loved to wear to look nice.
So, the two countries decided to have a special place where they could meet and trade. This special place was a small town called Kyakhta, which was right on the border of Russia and China. This way, both countries could come to Kyakhta and trade with each other without having to travel too far.
But because Russia and China were ruled by emperors, they had a lot of rules and regulations around trade to make sure everything was fair and nobody got cheated. So, people who wanted to trade at Kyakhta had to follow these rules very carefully.
For example, every year, a big group of Russian traders would come to Kyakhta and set up camp on one side of the town. Then, a big group of Chinese traders would come to the other side of the town. They would each bring with them the things that they wanted to trade, like furs and silk.
Then, they would start trading. But they had to be very careful to follow the rules, which included things like not cheating, not stealing, and paying taxes. They also had to communicate with each other even though they spoke different languages, which was hard, but they managed to do it.
Eventually, the Kyakhta trade became very successful and helped both Russia and China to become rich and prosperous. And even though it happened a really, really long time ago, it's still remembered as an important time in history when two countries were able to trade peacefully and fairly with each other.