Fork

Fork describes a situation where blockchain protocol rules change or different participants temporarily or permanently follow incompatible rules for building the chain.

Forks can result from software upgrades, protocol changes, or temporary chain divergence. Depending on compatibility between old and new rules, forks are commonly described as soft forks or hard forks.

Why forks occur

• protocol upgrades;
• changes to transaction or block formats;
• technical fixes;
• changes to network parameters;
• disagreements over protocol rules.

Not every fork creates two permanent blockchains. Temporary competing blocks can be resolved by the network consensus rules without producing a lasting split.