Important statement from bitcoin.org regarding the Bitcoin consensus protocol

Bitcoin is "a peer-to-peer electronic currency that allows payments to be made directly from one person to another online without going through any financial institution." Our vision is to expand the flexibility of the Bitcoin system to efficiently handle extremely large volumes of transactions while maintaining the core security and decentralization that makes Bitcoin unique.

We believe that in order for Bitcoin to achieve this goal, multiple layers of services must be built on top of it and connected to other systems. In addition, our long-term goal also includes protecting and increasing the privacy of Bitcoin users.

"Bitcoin Core" is an open source software project that directly inherits the original Bitcoin software settings. As a contributor to the project, we maintain and release software for the Bitcoin community for users to consider using. We are committed to improving Bitcoin's consensus protocol, and the upgrade plans we propose are all based on our perceived Bitcoin goals, are technically feasible, and have a reasonable chance of being widely supported and applied.

Bitcoin's consensus protocol can be changed through soft forks or hard forks (see Appendix A). Soft forks allow compatible changes, and new and old software can coexist on the network. Implementing new features through soft forks will not cause disruption, because only users who want to use the new features need to upgrade, and other users can continue to use the original software normally.

A hard fork will destroy the compatibility of all existing Bitcoin software, and all users must upgrade before a specified deadline, otherwise there is a risk of losing money. This situation may force users who do not upgrade to leave the network, and may cause various downstream software and applications to stop working, causing damage to the network effect of Bitcoin.

For these reasons, Bitcoin Core strongly favors compatibility and believes that it should be up to each user to decide whether to upgrade the Bitcoin software they are using. Virtually any new feature can be added via a soft fork. In some cases, a hard fork may have some benefits that, if agreed upon by nearly unanimous consensus, may outweigh its disadvantages. But aside from these rare cases, a soft fork is still the preferred option. We believe this is in the best interest of current and future users of the system.

As the Bitcoin ecosystem grows, we also expect that there will be more other software configurations that run the Bitcoin protocol, and inevitably these software projects may propose completely different solutions for the Bitcoin ecosystem to consider. Ultimately, the Bitcoin Core development team does not determine the consensus rules of Bitcoin; instead, it is up to Bitcoin users to choose what Bitcoin software they run. Therefore, Bitcoin Core deliberately does not have an automatic upgrade function, which ensures that each upgrade is voluntary for users, allowing users to maintain the power to choose what software to run.

Annex A

A hard fork is when a consensus rule is changed so that blocks that were invalid under the old rules may become valid under the new rules.

A soft fork means that after changing the consensus rules, blocks that were valid under the old rules may become invalid under the new rules, but all previously invalid blocks remain invalid.