Proof of Stake
Validators and staking.
Proof of Stake is a free Web3 & DApp Development Fundamentals lesson on CoddyKit — lesson 2 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Web3 & DApp Development Fundamentals learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Why an Alternative to PoW?
Proof of Work is secure but energy-hungry. Proof of Stake (PoS) seeks the same security guarantees while using a tiny fraction of the energy.
Ethereum switched from PoW to PoS in 2022 in an event called The Merge.
What Is Proof of Stake?
In Proof of Stake, the right to create a block is tied to how much cryptocurrency a participant locks up, or stakes, rather than how much computation they do.
Block creators are called validators, not miners.
Validators
A validator deposits a stake to participate in producing and attesting to blocks. On Ethereum, the required stake is 32 ETH per validator.
Validators propose blocks and vote (attest) that other blocks are valid.
Validator {
stake: 32 ETH
status: active
role: propose + attest
}Staking
Staking means locking up funds as collateral. This stake is the security deposit that keeps validators honest.
If you behave correctly you earn rewards; if you cheat, your stake is at risk.
Choosing a Block Proposer
The protocol pseudo-randomly selects one validator to propose the next block, often weighted by stake size.
Because selection is random and based on stake rather than hashing, there is no energy-intensive race.
Each slot:
proposer = randomSelect(
activeValidators,
weightedByStake)
proposer builds the blockAttestations
Other validators issue attestations — signed votes confirming a proposed block is valid and is the head of the chain.
When enough attestations accumulate, the block becomes part of the canonical chain.
Rewards
Validators earn rewards for proposing blocks and attesting on time. Rewards are paid in the network's native token.
This steady yield incentivizes honest, reliable participation.
Slashing
Slashing is the penalty for malicious behavior, such as proposing two conflicting blocks. The protocol destroys part of the offender's stake.
Slashing makes attacks financially painful — you literally lose money for cheating.
If validator double-signs:
burn part of stake
eject validator from setEconomic Security
PoS replaces PoW's energy cost with economic cost. To attack the chain, you must acquire a huge stake — and a successful attack would crash the very token you staked.
This makes attacking self-defeating.
Energy Efficiency
Because validators do not race to solve puzzles, PoS uses dramatically less energy than PoW — Ethereum's consumption dropped over 99% after The Merge.
This efficiency is PoS's headline advantage.
Putting It Together
Proof of Stake secures the chain with capital at risk instead of energy. Validators stake funds, propose and attest to blocks, earn rewards, and risk slashing for misbehavior.
Quick Check
Test your Proof of Stake knowledge.
Recap: Proof of Stake
You learned that:
- PoS ties block creation to staked capital, not computation
- Validators propose and attest to blocks
- Staking provides collateral; rewards pay honest behavior
- Slashing punishes misbehavior
- PoS is far more energy efficient than PoW
Next: other consensus mechanisms.
Frequently asked questions
Is the “Proof of Stake” lesson free?
Yes — the full text of “Proof of Stake” is free to read here on the web, and the Web3 & DApp Development Fundamentals course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Web3 & DApp Development Fundamentals course, upgrade to CoddyKit PRO.
What will I learn in “Proof of Stake”?
Validators and staking. You practise Web3 & DApp Development Fundamentals with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Web3 & DApp Development Fundamentals?
No prior experience is required. Web3 & DApp Development Fundamentals on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Proof of Stake” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Web3 & DApp Development Fundamentals lesson?
Yes. Every Web3 & DApp Development Fundamentals lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Proof of Work
- Proof of Stake
- Other Mechanisms
- Finality and Forks