A fork is a split in blockchain history or rules. A temporary split (race for the next block) usually heals. A is a backward-compatible rule change (tightens rules; old software can still accept new blocks; one compatible road can continue). A can leave two lasting chains with a shared past and different rules. Sources: Bitcoin glossary.
XRPL footnote (say so explicitly): protocol changes called need more than 80% of trusted validators for two weeks to enable; servers without the code become amendment-blocked. Source: Amendments.
Why it matters
After a contentious split, look-alike tickers and deposit addresses trick people into sending on the wrong chain.
How it works
Forks happen in a few ways. In a temporary split, two block builders finish at nearly the same moment, so for a short while, different nodes see different latest blocks. As more blocks arrive, the network follows the longer history and the other branch is dropped.
Rule changes are different. A soft fork tightens the rules, so blocks made under the new rules still look valid to older software. A hard fork changes the rules so older software rejects the new blocks. If some people never upgrade, two chains can keep running side by side, sharing history up to the split and then differing after it.
Real example: the XRP Ledger handles rule changes through amendments. Validators vote, and a change turns on only after it holds more than 80% support from trusted validators for two weeks. Servers that have not upgraded become amendment-blocked: they stop following the ledger instead of quietly starting a second chain. Sources: Bitcoin glossary, Amendments.
Amendment vote (XRPL)
An amendment enables after more than 80% of trusted validators for two weeks.
Validators vote
>80% for 2 weeks
Amendment-blocked
Step 1Validators vote,
Read all steps
Validators vote: Validators vote,
>80% for 2 weeks: and a change turns on only after it holds more than 80% support from trusted validators for two weeks.
Amendment-blocked: Servers that have not upgraded become amendment-blocked: they stop following the ledger instead of quietly starting a second chain.
Picture it
One highway dividing into two marked routes = hard fork risk. A rule update everyone can still read as valid traffic = (classroom wording). Short merge conflict that resolves = temporary split.
Watch out
Depositing to an exchange address on the wrong fork/chain because the icon looked identical.
