What is a Soft Fork?
The special feature of a Soft Fork: Changes and further developments of a blockchain towards the original version of the chain remain “backward compatible” with regard to a protocol and thus also remain traceable. The prerequisite is that users have a complete copy of the blockchain that was the starting point of the fork.
In contrast to a Hard Fork, it is sufficient if the majority of miners carry out this update. In the case of a hard fork, on the other hand, all nodes would have to carry out the respective upgrade.