Soft Fork

     A Soft Fork, as it relates to cryptocurrency and blockchain technology, is a change in a project’s protocol that is backwards compatible and doe not force its participants to upgrade their software if they want to continue to participate in the network.

     Soft Fork upgrades are typically changes that do not interrupt the core-most operations of the network’s consensus mechanism.

An Examples of soft fork protocol upgrade:
     Adjusting the block-size limit from 1 MB to 500 KB. (If the block-size increase of the upgrade interrupts the 1 MB limit then a hardfork must take place).