What Is an Orphaned Block?
An orphaned block is a valid block of transactions that has been rejected by the network because it does not have enough proof-of-work to be accepted. This can happen when two miners find blocks at nearly the same time, and one miner’s block is accepted while the other miner’s block is not. The rejected block then becomes an orphaned or “stale” block, as it cannot be added to the blockchain.
Orphaned blocks are still important for maintaining security on the blockchain, as they help prevent double spending attacks from occurring. When a new transaction is broadcast across the network, all nodes must agree on which version of history should be accepted in order to ensure consensus. If there were no orphans, malicious actors could potentially create multiple versions of history with conflicting transactions and fool some nodes into accepting them as legitimate. Orphans help protect against this type of attack by ensuring that only one version of history can exist at any given time.