soft fork (blockchain)

Definitions

1. A backward-compatible change to a blockchain's protocol where old nodes can still validate new blocks, even if they don't understand the new rules. Unlike a hard fork, the network doesn't permanently split — non-upgraded nodes simply see the new transactions as valid under the old rules.

   In plain English: A blockchain upgrade that doesn't force everyone to update. Old software still works with the new rules, so the network stays together.

   Example: The soft fork added SegWit to Bitcoin without requiring every node to upgrade, though it took months before most miners signaled support.

Related Terms

• Fork
• Upstream / Downstream
• hard fork (blockchain)