Proof of Work vs Proof of Stake: what’s the difference and why does it matter?

PoW secures a network via computational work; PoS secures it via staked value and validator selection. PoW tends to be energy-intensive and has different attack economics. PoS can improve throughput/energy efficiency but introduces staking, slashing, and validator centralization considerations. For developers, the consensus model affects finality, transaction fees, and security assumptions.