An orphan block (Orphan block) is a block that was rejected by the network during validation and did not enter the main chain of blocks. In a distributed system, miners around the world work simultaneously to find the next block, so situations where several valid blocks claim the same position at once are inevitable.

There can be several reasons for rejection. Sometimes a block contains incorrect information and fails to pass the check against the network's rules. More often, the reason is the race against time: if another block was found a few seconds earlier and more quickly received confirmation from the majority of nodes, the competing block remains outside the main chain.

What happens to the transactions

Transactions from an orphan block are usually not lost permanently: they return to the pool of unconfirmed operations and can be included in the next block. That is why experienced market participants recommend waiting for several confirmations before considering a transfer final. The appearance of such blocks is a normal property of how a decentralized network operates, not a sign of a malfunction.