Fork
What Is a Fork
A "fork" refers to a split in a blockchain’s protocol, resulting in two separate versions of the blockchain. Major forks can occur when developers or members of the community disagree on a project’s future direction, when software updates introduce changes that aren’t compatible with previous versions, or in the case of serious safety attacks. Forks are essential to how blockchains evolve, allowing for the introduction of new features, bug fixes, or even the creation of new cryptocurrencies.
There are two primary types of forks: hard forks and soft forks. A hard fork involves a significant change to the blockchain’s protocol that is not backward compatible. This means nodes (computers participating in the network) using the older software version cannot communicate with nodes running the new version. Hard forks usually result in two separate blockchains, each with its transaction history and often its cryptocurrency. One prominent example of a hard fork is the 2017 split between Bitcoin and Bitcoin Cash, which occurred due to disagreements over block size limits on the Bitcoin network, leading to the creation of Bitcoin Cash as a new cryptocurrency.
In contrast, a soft fork introduces a smaller, backward-compatible change to the blockchain. Nodes running the older version of the software can still validate transactions on the updated blockchain as long as they follow the new rules. Soft forks are typically used to implement new features or improvements without causing a full split in the blockchain. A notable example of a soft fork is the introduction of Segregated Witness (SegWit) on the Bitcoin network, designed to enhance scalability and transaction efficiency without splitting the network.