How is the fork implemented?

To understand the fork, we can break Bitcoin into two big chunks: the Bitcoin protocol (software) and the blockchain, which stores all transaction data.

The Bitcoin protocol (software) is completely open source. If you want to create your own branch blockchain (fork), you must first copy the Bitcoin protocol (software code), and then make appropriate modifications according to your needs.

Finally, Bitcoin forks can be made effective by specifying a block number. For example, it can be announced that the fork will take effect when the block number reaches 500000. When the block number is transmitted to the community, it will be divided into two parts, and some people decide to support the original protocol, and some people support forking the protocol, and then each group starts adding new blocks to the one blockchain they want to support.