Orphan Block

What is an Orphan Block?

One of the characteristics of orphan blocks is that they lack a parent block. There were earlier versions of the Bitcoin Core software that allowed nodes to receive blocks even if they didn't have any information about their genealogy. There are no more orphan blocks in Bitcoin after the release of Bitcoin Core v.0.10 in early 2015.

However, the phrase "orphan block" is still extensively used in the bitcoin community to refer to genuine mined blocks that have been thrown away. ' Most people refer to these blocks as orphan blocks since the client labels them as "stale blocks" or "extinct blocks," although this is incorrect. Since they have an established parent block, most people refer to these blocks as orphan blocks, instead of as stale blocks.

When two distinct miners almost simultaneously broadcast their legitimate blocks, stale blocks are formed. Because of this, the network is divided into two rival blockchains, each of which must be eliminated one at a time (the longest chain prevails while the other is abandoned). Even if both blocks have been verified and are valid, only one is part of the main chain at this point.

It's possible that a large number of fresh blocks are being generated and transmitted to the network at the same time. Information can take some time to travel between nodes in a distributed network. So, a group of nodes could choose to validate one block while another group chooses to validate the other. This is possible because of this. Finally, one of the blocks would become "orphaned" as a result.

Creating stale blocks is a normal occurrence that is almost always the result of random chance. Although they can be created by malevolent players in an effort to construct an alternate valid chain, they are also possible (see 51 percent attacks).