Fork

Definition

Fork has several related meanings in cryptocurrency discussions. A temporary chain fork occurs when different valid blocks extend the same predecessor and nodes initially see competing branches. Bitcoin resolves these situations by following the valid branch with the greatest accumulated proof of work, potentially removing a recent block from the accepted history. A protocol fork instead concerns a change to validation rules; hard forks and soft forks describe different compatibility relationships between old and new rules. A software fork is simply a separate development branch or copy of a codebase and need not create a new blockchain at all. These meanings should not be mixed together. A routine competing block does not automatically create a lasting new cryptocurrency, and a proposed software change does not establish that users have adopted new consensus rules. Context determines what a particular fork announcement actually implies.