Educational Post: What is a Soft fork? A soft fork is a bac | Mazim Crypto Academy channel

Educational Post:

What is a Soft fork?

A soft fork is a backward-compatible upgrade, meaning that the upgraded nodes can still communicate with the non-upgraded ones. What you typically see in a soft fork is the addition of a new rule that doesn’t clash with the older rules.
For example, a block size decrease can be implemented by soft-forking. Let’s once again draw on Bitcoin to illustrate this point: though there’s a limit on how big a block can be, there isn’t a limit on how small it can be. If you want to only accept blocks below a certain size, you just need to reject bigger ones.
However, doing so doesn’t automatically disconnect you from the network. You still communicate with nodes that aren’t implementing those rules, but you filter out some of the information they pass you.

A good real-life example of a soft fork was the aforementioned Segregated Witness (SegWit) fork, which occurred shortly after the Bitcoin/Bitcoin Cash split. SegWit was an update that changed the format of blocks and transactions, but it was cleverly crafted. Old nodes could still validate blocks and transactions (the formatting didn’t break the rules), but they just wouldn’t understand them. Some fields are only readable when nodes switch to the newer software, which allows them to parse additional data.

Even two years after SegWit activation, not all nodes have upgraded. There are advantages to doing so, but there’s no real urgency since there’s no network-breaking change.