Blockchain is decentralized such that there is no central control or central authority.That been said,each node is independent and free to suggest changes.This changes could be for the betterment of that particular blockchain.
A fork is a situation where the developers,miners and users of a blockchain wants to make changes in the way that the blockchain works.This changes could result in creating a new version thus having two different versions or the change will only be in form of amendment the blockchain continues to run after the amendment.
If the changes result in the creation of a different blockchain with a new token,we call it a hard fork.
On the other hand,if the changes involves the modification and continuation of the blockchain,and maintaining the token,we call it a soft fork.
It is a permanent change/upgrade to the software protocol of a blockchain such that an entirely new version is created.In this case owners of the old version does not accept the new version and the owners of the new version does not accept the old version.Nodes of the old version does not accept the new version of the blockchain and vice versa. In a hard fork, two different tokens must exist,which is the old token and the newly created token.
The holder of the new version sees the block of the old version as an invalid block also holders of the old version sees the block of the new version as an invalid block.
It is important to note that when a hard fork takes place,users that moved to the new version can still hold the old tokens,their token balances would be granted although miners will decide if they will verify old blocks or the new one.
The reasons for a hard fork is to correct and improve some anomalies or limitations like scalability or transaction cost on the old blockchain.It could also be for the purpose of correcting security threats in the old blockchain.
An Example of a Hard Fork
An example of a hard fork is the Bitcoin(BTC) fork that happened in 2017 which resulted in the creation of a new network called Bitcoin Cash(BCH). Presently we have an old version called Bitcoin and the token is BTC and new version created from the fork which is called Bitcoin Cash with its native token as BCH.
The main reason for the hard fork was to increase the scalability (number of transaction per second) of BTC by increasing the block size to accommodate more data.Some nodes and developers did not like the proposed changes and so they remained in the BTC network while the others agreed and moved to the BCH network which was implemented with the 2017 hard fork.
Evidence to prove that BCH is a hardfork of BTC
If we look at the first ever block(genesis)in the BTC network,you will see the date to be 2009-01-03 and the time is 19:15.See the evidence on Bitcoin Explorer
Also notice that the genesis block of the BCH does not have a different date and time rather it has the exact date and time as the BTC genesis block which shows that BCH was a hardfork of BTC.See the records on Bitcoincash Explorer
- WHY HARD FORK IS IMPORTANT IN THE BLOCKCHAIN
As humans we yearn for improvement and a better life.The developers,nodes and miners on the blockchain want changes to make things better or to upgrade to a better version.
A hard fork is a practical application of decentralization.It is important to the blockchain because it helps to make changes that will give birth to a more faster,reliable, independent and efficient blockchain.It also leads to the creation of a new token thereby bringing a healthy competition In the blockchain industry.
The Bitcoin hard fork is important because the new version which was created will improve the number of transaction that can be completed in a second.So the hard fork will:
•Increase the scalability of the old blockchain
•Increase the block size of the old blockchain
- WILL THE EXISTENCE OF BLOCKCHAIN BE POSSIBLE WITHOUT A HARD FORK
Definitely, the existence of a blockchain would still be possible without a hard fork.Infact the Bitcoin blockchain has been in existence since 2009 before the hard fork of Bitcoin Cash that happened in 2017.
There is a similar term to hard fork which is called a soft fork.In soft fork there is no creation of a new blockchain or a new token.The old network is just upgraded and it continues to run as one blockchain with one token.
An example of a soft fork is the Bitcoin Segregated Witness (SegWit) which exclude witness signatures on each block so as to accomodate more transactions and improve speed.
- IS IT POSSIBLE TO IMPROVE A HARD FORK
It could be possible to improve a hardfork.Although a hard fork is already a decent blockchain concept because it helps to improve the limitations of already existing blockchains by making it better and creating a new token.
The best way to improve a hard fork is to create another hard fork so as to improve on the existing ones.For example having a hard fork of Bitcoin Cash,to work on its deficiencies inorder to make it better and create a newer token.
Change is constant.Miners,developers and nodes like to get a better deal for each network.There is always a need to work on the deficiencies of already existing blockchains by creating a new version with a new token or disagree to changes brought to an existing blockchain.This will bring a healthy competition by forcing each version to perform better.Bitcoin Cash(BTC) is an example of a hard fork of Bitcoin(BTC).
Hive blockchain is a hard fork of Steem blockchain.The hard fork happened because Hive developers did not welcome the incorporation of Tron to Steemit.This separation has brought a healthy competition between Steem and Hive blockchain.Steem token and Hive token compete in the market.