WHAT IS A BLOCKCHAIN FORK?
Recently I have been very interested in the upcoming cryptocurrency Hedera Hashgraph (HBAR) because of its promise of low gas costs and innovative new Hashgraph Consensus Algorithm. In my research of this fascinating new network I have come across a few terms that I hadn’t come across before. The first of these terms was a “blockchain fork.” While looking into the term I found that it has come to mean a multitude of different things which I hope to effectively explain in this article.
WHAT IS A FORK?
As a generalized definition a blockchain fork is a change in protocol or rules implemented on the blockchain. A fork can occur with or without the consensus of all nodes on the blockchain and in some cases new blockchains are created as a result. A prime example of a fork that did not involve a full consensus of nodes on the network was the Ethereum to Ethereum Classic split. The change in protocol, or fork, that was not in consensus in that case was the reversal of a hack that threatened many Ethereum users’ funds. Ethereum Classic users were against the reversal of the hack because they believed it threatened the integrity and the mission of the Ethereum blockchain. The example of Ethereum vs Ethereum classic is what is referred to as a hard fork but there are actually two types of fork.
TYPES OF FORK?
The Ethereum split was a hard fork but what exactly does that mean? A hard fork is a fork in which all nodes must update to a new protocol (software, hardware, ruleset, etc). If a node does not update to the new protocol it can no longer validate transactions on the blockchain. In the case of some hard forks previously valid blocks may even be considered no longer valid. In contrast to the hard fork there’s what is known as a soft fork. A soft fork is a change in protocol that is recommended but not fully enforced. Old nodes on the network will still be able to validate transactions just like updated nodes.
ALTERNATE DEFINITION OF FORK?
The term fork as it refers to the blockchain actually has one alternate definition as well. A fork can also occur on a blockchain when two blocks have the same block height. This occurs when two nodes mine a block at the exact same time. Certain blockchains do not allow for blocks to be the same block height so a fork in this case is the determination of what to do with one of the blocks. In some cases the block is dropped completely and in others it is orphaned where it does not end up on the main blockchain but it is considered a valid block. This is the type of blockchain forking that a network like Hedera Hashgraph aims to solve. A blockchain fork can clearly mean a multitude of different things but hopefully this article will help you decipher the meaning when you encounter the term blockchain fork in the future.
