I know it’s confusing for a lot of people who don’t have a background in software development or computer science. It helps to have a little bit of background.
Hard forks do not always create a new coin, but every time there’s a hard fork there’s a possibility of a new coin. In reality, the majority of hard forks do not create a new coin. The public generally only hears about hard forks which make a new coin, though, so they feel it’s very common when it’s not - and a lot of people fear any hard forks because they are afraid of their favorite coin splitting into two different coins.
This post may help you understand:
I think the confusion largely comes from the fact that in coding and computer science we use the words “fork” and “hard fork” in particular ways which are not how the general public uses them.
A “fork” just means a copy of something with something different. It’s simply a computer science term for making a copy with your own changes.That’s all!
If you like a song, but you change a few words to make your own personal version, you have “forked” the song. If many people make their own version of a song, and they all post the song online, it’s possible to draw a sort of “family tree” of the different versions of the song. You can find the original song which a lot of people copied, and you can find that some people made their versions based on someone else’s copy instead of the original. It will look like a person’s family tree, or like a biological tree of different species. On those trees, every intersection is just a “fork.” That’s where the term comes from - it means nothing more.
So a fork is just a copy with some changes. What’s a hard fork?
A hard fork is a change which requires everyone to use the new version. For example, BTG version 15.0 used the original version of Equihash (200,9), and the newer BTG version 15.1 used Equihash (144,5). This means that if you use one version and I use the other version, you and I are not compatible. Yours can work, and mine can work, but we cannot share blocks any longer. Both versions can potentially continue to work and grow blocks, but they can never be the same chain any more. So there is the possibility for a split and two different coins, but that only happens if different people insist on running both versions.
But if people do not insist on running both versions - if everyone agrees on the new version and nobody runs the old version, then there is no split, and no new coin! This is the key - if everyone in the coin community agrees that the new version is better and appropriate, and everyone runs it and mines it, and nobody mines the old version - then there is no split and no new coin. It’s simply an upgrade. That’s why we’ve called our new code this summer a “successful hardfork upgrade.”
I hope this helps.