Proof of work

Proof of work is a consensus method in which participants compete to solve a hard computational puzzle, and the first to find a valid solution earns the right to add the next block. The puzzle is costly to solve but cheap to verify, so honest effort is rewarded while tampering becomes expensive. It secures networks by tying block creation to real energy and hardware.

A common misconception is that the computation performs useful external work; it mainly demonstrates effort. For a comparison with the staking-based alternative, see proof of work vs proof of stake.