What is the fundamental difference between a soft fork and a hard fork. A fork is a condition whereby the state of the blockchain diverges into chains were a part of the network has a different perspective on the history of transactions than a different part of the network. That is basically what a fork is, it is a divergence in the perspective of the state of the blockchain.

What Is A Soft Fork?
Whenever a chain needs to be updated there are two ways of doing that: a soft fork or a hard fork. Think of soft fork as an update in the software which is backwards compatible. What does that mean? Suppose you are running MS Excel 2005 in your laptop and you want to open a spreadsheet built in MS Excel 2015, you can still open it because MS Excel 2015 is backwards compatible.

BUT, having said that there is a difference. All the updates that you can enjoy in the newer version won’t be visible to you in the older version. Going back to our MS excel analogy again, suppose there is a feature which allows to put in GIFs in the spreadsheet in the 2015 version, you won’t see those GIFs in the 2005 version. So basically, you will see all text but won’t see the GIF.

What Is A Hard Fork?
The primary difference between a soft fork and hardfork is that it is not backward compatible. Once it is utilized there is absolutely no going back whatsoever. If you do not join the upgraded version of the blockchain then you do not get access to any of the new updates or interact with users of the new system whatsoever. Think PlayStation 3 and PlayStation 4. You can’t play PS3 games on PS4 and you can’t play PS4 games on PS3.