How Does a “Chain Split” Occur and How Is It Resolved by the Longest Chain Rule?
A chain split, or temporary fork, occurs when two or more miners find a valid block almost simultaneously, leading to two different chain tips. This is a natural part of decentralized mining.
The longest chain rule resolves this by having all nodes temporarily hold both chains until one of them finds the next block. Once a subsequent block is found, the chain it extends becomes the longer one, and the shorter chain's block is orphaned, with the network quickly converging back to a single, longest chain.
Glossar
Longest Chain Rule
Consensus Rule ⎊ Longest Chain Rule is the fundamental protocol mechanism dictating that in the event of a temporary fork, the chain exhibiting the greatest cumulative proof of work or stake is recognized as the canonical and valid history, thus finalizing transactions.
Longest Chain
Consensus ⎊ The longest chain rule is the core mechanism for achieving consensus in Proof-of-Work systems like Bitcoin.