A soft fork is a type of blockchain protocol update that is backward-compatible, meaning that nodes running the old version of the software will still recognize the new blocks as valid. This type of fork allows for an upgrade to the blockchain without causing a split, as both updated and non-updated nodes can continue to operate on the same network. Soft forks typically involve changes that tighten the rules of the protocol, making previously valid transactions invalid without disrupting the entire network. An example of a soft fork is the Segregated Witness (SegWit) update in Bitcoin, which aimed to improve transaction capacity and scalability without creating a new blockchain. Soft forks are often favored for implementing improvements because they maintain network unity while allowing for gradual adoption of new features and optimizations.
