Topic: What is HardFork, SoftFork? - page 2. (Read 523 times)

What is 'Hard Fork'
A hard fork (or sometimes hardfork), as it relates to blockchain technology, is a radical change to the protocol that makes previously invalid blocks/transactions valid (or vice-versa). This requires all nodes or users to upgrade to the latest version of the protocol software. Put differently, a hard fork is a permanent divergence from the previous version of the blockchain, and nodes running previous versions will no longer be accepted by the newest version. This essentially creates a fork in the blockchain: one path follows the new, upgraded blockchain, and the other path continues along the old path. Generally, after a short period of time, those on the old chain will realize that their version of the blockchain is outdated or irrelevant and quickly upgrade to the latest version.

What is 'Soft Fork'
In terms of blockchain technology, a soft fork (or sometimes softfork) is a change to the software protocol where only previously valid blocks/transactions are made invalid. Since old nodes will recognize the new blocks as valid, a softfork is backward-compatible. This kind of fork requires only a majority of the miners upgrading to enforce the new rules, as opposed to a hard fork which requires all nodes to upgrade and agree on the new version.

Hard Fork...

https://www.investopedia.com/terms/h/hard-fork.asp

SoftFork....

https://www.investopedia.com/terms/s/soft-fork.asp

Soft fork and hardfork have some similarities in that they occur when there is a change to the existing protocols which can occur as a result of situations like risk security issues, general consensus etc.
One major difference however is that in Soft fork there is backward compatible change to the protocol which means user need not upgrade immediately but in Hardfork the reverse is the case. There's is no background compatible change to the protocol and so to avoid glitches, upgrade is more often than not required.

Soft fork = backward compatible change to protocol.
Legacy nodes can still (mostly) verify transactions and blocks and do not necessarily need to upgrade immediately.
Used to introduce new features to the code

Hard fork: also used to introduce (of remove ) features to the protocol, but it's not backwards compatible.
Causes a divergence because new rules aren't compatible with the old ones (eg a 2MB block size increase in bitcoin isn't compatible with the current consensus of 1MB block size, so legacy nodes will reject any block greater than 1MB)
If it isn't contentious -- eg, in Monero-- then (almost) all nodes upgrade to the new chain  and the old one dies a chain death.
However, if it is contentious, and not everyone migrates to the new chain then there will be 2 different chains with 2 consensus rules. This is called a chain split.
I assume you're referring to a UTXO fork here where coins (or precisely UTXOs) in the legacy chain are present in the new chain.
Technically all hard forks are UTXO forks as long as it's not just a codebase fork.
Since the 2 chains share the same block height then they'll share the same transaction history and UTXO set.
So, yes, if you make a UTXO fork of a coin, they will be present on the new chain automatically.

Love the wiki for quickfire and reasonably adequate explanations!

My added understanding, possibly not incredibly accurate.

That is one of the scenarios for a hardfork, but not the only one. It is possible for a hard fork to occur with consensus, i.e. all current users (nodes in this case) support the fork and everyone upgrades software following new rules, as I understand, usually because of a critical security risk.

A technical hard fork could also happen inadvertently via blockchain reorganisation (client discovers longer chain and abandons shorter one). Unlikely to ever happen again at current network growth but I read that this happened at least once already even with Bitcoin on 12 March 2013... and I see can be common with alts.

as far as i know mining will not stop.
 softfork is a change to the bitcoin protocol wherein only previously valid blocks/transactions are made invalid. Since old nodes will recognize the new blocks as valid, a softfork is backward-compatible. When a majority of miners upgrade to enforce new rules, it is called a miner-activated softfork (MASF). When full nodes coordinate to enforce new rules, without support from miners, it is called a user-activated softfork (UASF).

 A hardfork is a change to the bitcoin protocol that makes previously invalid blocks/transactions valid, and therefore requires all users to upgrade.

Any alteration to bitcoin which changes the block structure (including block hash), difficulty rules, or increases the set of valid transactions is a hardfork. However, some of these changes can be implemented by having the new transaction appear to older clients as a pay-to-anybody transaction (of a special form), and getting the miners to agree to reject blocks including the pay-to-anybody transaction unless the transaction validates under the new rules. This is known as a softfork.

To date, Bitcoin has never deployed a hardfork, but some altcoins have.

SOURCE: bitcoin wiki

hardfork occur  when some people supporting that coin is  not satisfy to the current protocol.

Exactly what happen when they occur?

Mining stopped?

Coin balance of owners will be transferred to new wallet automatically?