Definition
Proof of Work requires miners to expend computational energy solving mathematical puzzles. The first miner to find a valid solution earns the right to add a block and receive a block reward (newly minted coins plus transaction fees). PoW provides strong security through economic cost—attacking the network requires controlling 51%+ of mining power. Bitcoin uses PoW; Ethereum transitioned to Proof of Stake in 2022.
lightbulb Example
Bitcoin miners collectively consume ~150 TWh annually—comparable to a medium-sized country—competing to solve SHA-256 puzzles. The winning miner earns 3.125 BTC (approximately $200K+) per block, creating strong economic incentive to secure the network.
verified_user Key Points
- Miners solve cryptographic puzzles to validate blocks
- Energy-intensive but provides strong security
- 51% attack requires controlling majority of hash power
- Bitcoin's consensus mechanism