Honest nodes, liars, and the race to agree.

Proof-of-work “votes” with electricity: every block is a solved puzzle, and the chain with the most total work is treated as truth. Short-lived ties are normal when two blocks appear close together; the next block tips the balance and the lighter branch’s blocks turn stale (no rewards, transactions vanish).

Depth = safety. Each block buried under more successors costs extra work to rewrite. A 3-block gap here mirrors the idea of “N confirmations” in real chains: wallets and exchanges wait for depth so an attacker would need to redo that work and still get ahead, which quickly becomes uneconomic.

If an attacker produces more work (e.g., >50% hashpower) and reaches the gap first, their fork becomes canonical and honest blocks are orphaned—this is how double-spends happen. Communities can manually reject an attack with a social fork or checkpoint, but that’s an override of the default “most work wins” rule and can invalidate recent user transactions on either side.