What is fork?
Along with the development of the cryptocurrency market, new terminology has appeared. In addition to bitcoin, which is already familiar, altcoin and fork are also familiar to everybody.
Fork, derived from the name of the commonly used utensil, means the conversion of the bitcoin program code. Since the bitcoin code is open, any user is able to change it using the source code at his discretion. In particular, one can change the rules by which separate blockchain blocks are recognized as valid (genuine). Any change of these rules is called a fork. There are such types of forks:
• Soft, or soft-fork
• Hard, or hard-fork
If there′s no need to update the software to execute the changed rules, such change is called soft, or soft-fork. Even if the network nodes, which work under the same rules, will be able to maintain interaction with the nodes that have taken the changes.
If you draw an analogy with languages, you can imagine that before the fork all the nodes communicated in
Castilian Spanish, and then some of them began using the Cuban dialect. Subsequently, despite certain peculiarities and nuances, all the nodes (both those that have begun using the Cuban version, and those that haven’t) will be able to understand each other without any problems.
Soft-fork is a reversible code change, without violating the basic protocol rules.
If, as a result of the change, the new rules conflict with the former ones so that the nodes that act under the old rules are not able to get the data from the nodes that took the fork – such change is called the hard one, or hard-fork.
Returning to the language analogy, nodes with the old rules speak Spanish, and those nodes that have adopted new rules speak Korean.
Hard-fork changes the very consensus mechanism and the rules for recognizing the blockchain bocks genuine. As a result, the network is divided into two parts, which will no longer be able to interact, since the blocks recognized as genuine on the same subnet, will never be the same for the other.
Any cryptocurrency except for bitcoin is generally referred to as altcoin. It is stipulated that it is not just a copy of the existing cryptocurrency. It is implied that altcoin has significant improvements in technical characteristics and a desire for a worldwide singularity.
With that the meaning of the terms altcoin and fork is rather inaccurate, which means that these names can be used regardless of how accurately they correspond to the definition. Quite often they stand for the same project.