Tiandihui is a Chinese secret society that started a long time ago when China was ruled by emperors. A secret society is a group of people who hide their activities from others and only talk about their plans with the people in their group. Tiandihui was formed by people who were unhappy with the way the government was running things and wanted to make their own rules.
Think of Tiandihui as a club with rules and a secret handshake. People who wanted to join had to follow certain rules and agree to keep secrets. They also had to be loyal to the club and help other members when they needed it. The secret handshake was a way to identify other members without revealing who they were to outsiders.
Over time, Tiandihui grew in size and became very powerful. They had their own code of conduct, which included helping the poor and overthrowing corrupt government officials. Tiandihui members helped each other by giving money, finding jobs, and providing protection if someone was in trouble. But they also had a darker side, as they sometimes used violence to achieve their goals.
The Chinese government didn't like Tiandihui and considered them a threat to their power. They tried to stop the group by banning it, but Tiandihui continued to operate secretly. Tiandihui was eventually forced to go underground during the Communist Revolution in 1949.
Today, Tiandihui is still active in some parts of the world, although it's not as powerful as it used to be. Some people still see it as a way to help their community and protect their interests. Others see it as a criminal organization. Whatever the case may be, Tiandihui remains a fascinating part of Chinese history and culture.