What Is a Hard Fork? Understanding Blockchain Changes Made Simple

What Is a Hard Fork? Simple Guide for Crypto Beginners The easiest way to describe what is a hard fork is through the explanation of it being a drastic change in the blockchain rules that make a blockchain incompatible with its former version. After that, nodes have to choose what chain to continue to build upon. This notion of a demanding fork is especially important to understand the reasons why there are some crypto projects, for example, Bitcoin Cash or Ethereum Classic. Deciphering the Definition of a Hard Fork in Crypto It is time to explain in detail what is a hard fork. Any blockchain operates using a certain protocol. To implement a new function, fix a bug, or make any other drastic change, blockchain developers have to alter this protocol in a way to make a new chain incompatible with the previous version. This process is called a hard fork. Old nodes will not be able to verify transactions on the new chain, and vice versa. It is different from a soft fork, as a soft fork does not break the chain and is backward compatible. Features of a Hard Fork Here are several major characteristics of a fork that can help to distinguish it from others: Chain split: Old and new chains become independent after the fork's activation. Non-backward compatible rules: Old nodes cannot verify blocks in the new chain without upgrading. Community-driven:Mining pools, developers, and nodes reach an agreement on making changes. Possibility of creating a new coin: If a large number of community members continue to operate on the old chain, you will get two coins, like Bitcoin and Bitcoin Cash. Upgrade is mandatory: Users have to upgrade their software to join the new chain. Why Does a Hard Fork Happen? As a matter of fact, people often wonder what is a hard fork needed for. There are various reasons for the decision to make a fork. Developers may need it to patch a security flaw, to implement a new feature, or to solve some other problem that the old software is unable to handle. Sometimes, a disagreement between community members can trigger a fork. An example of this case is Ethereum's hard fork in 2016 after the DAO hack. This event led to splitting the chain into Ethereum (ETH) and Ethereum Classic (ETC). The Technology Behind a Hard Fork Knowing what is a hard fork in theory, we can now move on to its practical sides. First of all, the developers propose changes to the chain and define activation block height or activation date. Prior to that moment, mining pools, developers, and exchanges update their software to the new version.