Since its birth, the bitcoin ecosystem has seen numerous debates on the right protocol changes required to continue its success. A couple of months ago, we were all witness to one of the first hard forks, which created an entirely separate digital currency known as Bitcoin Cash (BCC), following a new protocol.
This has happened yet again, as on October 25th 2017, Bitcoin Gold seceded from the bitcoin blockchain, into a new digital currency. The main difference about it is its new proof-of-work algorithm.