A Hard Fork, as it related to cryptocurrency and blockchain technology, is a radical change in the protocol that is not backwards compatible and forces its participants to upgrade their software if they want to continue to participate in the network.
Whenever a hard fork takes place, a duplicated version of the original chain appears and now two versions of the chain exist. Participants of the original network all received mirrored accounts the new chain and are balanced with an equal amount (1:1) of the new network’s currency.
Examples of protocol changes that warrant Hard-Forks:
– Block size – Confirmation Time
– Block time – permissibility to join
– Hashing Functions