Every blockchain needs a rule for who adds the next block. Proof-of-Work weights that choice by computing power; Proof-of-Stake weights it by staked tokens. In both, your chance of being picked is your share of the resource. Run rounds and watch blocks-won converge to each participant's share.
Miners race to find a valid nonce. The more hash power you have, the more likely you find it first.
A validator is chosen at random, weighted by stake. The more you stake, the more often you're picked, and the more you'd lose by cheating.
| Property | ⛏ Proof of Work | 🪙 Proof of Stake |
|---|---|---|
| Selection | Computing-power race | Weighted random by stake |
| Energy use | Very high (ASICs, GPUs) | Very low (~99.9% less) |
| Security model | 51% of hash power | 51% of staked tokens |
| Entry barrier | Hardware cost | Token stake (32 ETH on Ethereum) |
| Finality | Probabilistic (~6 blocks) | Checkpoint-based, faster |
| Misbehavior | Wasted energy only | Slashing (stake burned) |
| Used by | Bitcoin, Litecoin, Monero | Ethereum, Cardano, Solana |