soft fork or Soft-Forking Change is a temporary fork in the blockchain which commonly occurs when miners using non-upgraded nodes don't follow a new consensus rule their nodes don’t know about.
Not to be confused with fork, hard fork, software fork or Git fork.
Stale Block::
stale block::
Block which were successfully mined but which isn’t included on the current best block chain, likely because some other block at the same height had its chain extended first.