Hard Forks vs Soft Forks: Understanding Blockchain Upgrades

A hard fork is a significant change to a blockchain's rules that makes old software obsolete, potentially splitting the network in two. A soft fork, on the other hand, tightens or adds rules without making old software unusable, keeping the network intact.

The difference between these two types of forks matters greatly for cryptocurrency holders. A hard fork can result in a new coin being created overnight, while a soft fork may alter how an existing wallet behaves but is unlikely to create a new coin.

To understand which type of fork has occurred, one should consider whether old nodes reject the new blocks, whether the change requires everyone to upgrade or just a majority, and whether the network ends up with one chain or two. A hard fork can lead to a split in the blockchain, creating two separate networks and coins if enough participants refuse to upgrade.

The Ethereum DAO hard fork in 2016 serves as an example of how a disputed upgrade can result in two chains. The Bitcoin Cash split from Bitcoin in 2017 is another notable instance of a hard fork leading to a new chain.