Consensus mechanism
The consensus mechanism in the blockchain was born to solve the problem of "who will keep the books". In traditional transaction systems, such as Alipay, there is a central entity to record every transaction in the system.
But there is no center in the blockchain, so who is responsible for recording everyone's transaction information on the chain? To solve this problem, it is necessary to formulate a rule for selecting bookkeepers. This rule is called a consensus mechanism.
The first public chain Bitcoin uses the "workload proof mechanism".
This mechanism is like this. Give you a random number. Whoever calculates it first will get the right to keep accounts. In other words, whoever has the greater computing power is more likely to become the bookkeeper. The result of this is that the accounting candidates are all caught in a "computational power competition", and they keep accumulating computing power until in the end most of the computing power is contracted by a few people.