What Is a ‘Fork’ in a Blockchain and How Does Difficulty Adjustment Relate to It?

A fork occurs when a blockchain splits into two potential paths, typically due to a disagreement in protocol rules (hard fork) or two miners finding a block at nearly the same time (soft or temporary fork). Difficulty adjustment is key to resolving temporary forks in Proof-of-Work.

The chain with the highest accumulated difficulty (the 'longest chain') is considered the canonical one, incentivizing miners to abandon the shorter, less difficult chain.