What Is an Orphan Block?
An orphan block is a solved or valid block in the blockchain that is later rejected by the blockchain network. As such, these blocks do not form part of the main blockchain.
Orphan blocks are formed in several situations. One of the most common causes of orphan blocks occurs when two miners solve a block simultaneously. The miner who presents the more detailed proof-of-work is awarded the block reward while the other block is rejected.
Orphan blocks are also known as stale blocks or detached blocks.
A Deeper Look at This Term
During the mining process, miners compete to generate new blocks by solving complex mathematical functions. The first miner to solve the problem gets their block added to the blockchain and receives the block reward. This is the backbone of every proof-of-work blockchain.
However, a situation may occur where two miners produce a block at the same time (or within a similar time). This usually happens because newly formed blocks in the blockchain are not accepted instantaneously. During the time lag for acceptance of a new block, another miner may also solve the same block.
When this happens, the nodes must decide which of the two blocks newly formed blocks to accept. The block with the larger proof-of-work share is most often accepted, while the other is discarded from the chain and deemed an orphan block. While these blocks are technically valid, they are rejected due to delayed acceptance.
← Back to Dictionary
