Proof of work and proof of stake are two different validation techniques used to verify transactions before they’re added to a blockchain that reward verifiers with more cryptocurrency. Cryptocurrencies typically use either proof of work or proof of stake to verify transactions.
Proof of Work
“Proof of work is a method of verifying transactions on a blockchain in which an algorithm provides a mathematical problem that computers race to solve,” says Simon Oxenham, social media manager at Xcoins
Each participating computer, often referred to as a “miner,” solves a mathematical puzzle that helps verify a group of transactions—referred to as a block—then adds them to the blockchain leger. The first computer to do so successfully is rewarded with a small amount of cryptocurrency for its efforts.
This race to solve blockchain puzzles can require an intense amount of computer power and electricity. In practice, that means the miners might barely break even with the crypto they receive for validating transactions, after considering the costs of power and computing resources.
Proof of Stake
To reduce the amount of power necessary to check transactions, some cryptocurrencies use a proof of stake verification method. With proof of stake, the number of transactions each person can verify is limited by the amount of cryptocurrency they’re willing to “stake,” or temporarily lock up in a communal safe, for the chance to participate in the process. “It’s almost like bank collateral,” says Okoro. Each person who stakes crypto is eligible to verify transactions, but the odds you’ll be chosen to do so increase with the amount you front.
“Because proof of stake removes energy-intensive equation solving, it’s much more efficient than proof of work, allowing for faster verification/confirmation times for transactions,” says Anton Altement, CEO of Osom Finance.
If a stake owner (sometimes called a validator) is chosen to validate a new group of transactions, they’ll be rewarded with cryptocurrency, potentially in the amount of aggregate transaction fees from the block of transactions. To discourage fraud, if you are chosen and verify invalid transactions, you forfeit a part of what you staked.