Bitcoin is not replicable

In the real world, if you give someone a 100 yuan bill, you will no longer have it. But everything in the digital world is reproducible. If you copy a file to someone else, you still have the file. If you copy 100 yuan to someone else, you still have 100 yuan (this is called double-spending). This leads to the fact that money in the digital world must be managed in a centralized way, such as by the central server of a bank to manage your money.

But Bitcoin solves this problem. If you give someone a bitcoin, you no longer have it. If you try to pay someone else another bitcoin, the surrounding nodes will check that you actually have no bitcoin and refuse to spread your illegal payment. The breakthrough of Bitcoin is that for the first time in the digital world, something that is neither reproducible nor centralized has been created. Bitcoin and electronic legal tender are completely different things. Bitcoin is the first real digital currency.

Online legal tender (Alipay or online banking) is not a real digital currency. The money you have in online banking is just a mapping of banknotes in reality. It is rooted in reality, while Bitcoin is rooted in the digital world. Bitcoin is an irreversible invention. What is an irreversible invention? It means that when it does not exist, it is nothing, but once it appears, the world cannot return to the state without it. Wheels, sewers, flush toilets, gears, engines, copiers, the Internet, mobile phones, sensors, social software, etc., are all such inventions. When they do not appear, no one will think that the world is missing something, but once they appear and are invented, people start to use them. Once some people start to use them, the world will no longer lack these things, and people will even feel that they can't move forward without them (excerpted from Li Xiaolai's "Bitcoin World Survival Guide (Advanced)").