What is a hard fork?

A hard fork in blockchain technology is a radical change to a network’s protocol that makes previously invalid blocks and transactions valid, or vice-versa. A hard fork requires all nodes or users to upgrade to the latest version of the protocol software. Forks may be initiated by developers or members of a crypto community who grow dissatisfied with functionalities offered by existing blockchain implementations.

There are a number of reasons why developers may implement a hard fork, such as correcting important security risks found in older versions of the software, to add new functionality, or to reverse transactions.

Hard forks and soft forks are basically the same in the sense that an old version remains on the network while the new version is created. However, with a soft fork, only one blockchain will remain valid as users adopt the update. Whereas with a hard fork, both the old and new blockchains exist side by side, which means that the software must be updated to work by the new rules.

Electra Protocol did not have to implement any hard fork yet. The upcoming release of the smart contracts platform, for example, will most likely require a hard fork in order that the chain can support programmable contracts.