Proof of Work (PoW) is a cryptographic proof mechanism for securing blockchains, gaiting the right to add blocks, and preventing Sybil attacks. Although often considered a consensus protocol in itself, Proof of Work, and other similar proof mechanisms, do not determine consensus themselves, although they may help facilitate the process. Under a Proof of Work system, miners contribute 'work' in the form of hash rate by dedicating computational power towards solving cryptographic hash puzzles, producing incremental blocks. Proof of Work operates through a hashing competition, where each node competes to find a hash value for a block that is less than the dynamically-adjusted target. The first node to generate a valid hash processes the block and propagates it to the network, typically receiving a reward as compensation for their work.