Proof of work and proof of stake are two different approaches blockchains use to reach agreement on which transactions are valid, a problem known as consensus. Bitcoin uses proof of work, where miners compete using computing power to solve a puzzle, and the winner adds the next block in exchange for a reward.
Proof of stake, used by networks like Ethereum since 2022, instead selects validators largely based on how many coins they have locked up, or staked, as collateral. Validators who approve fraudulent transactions risk losing part of their staked coins, which creates a financial incentive to act honestly.
The practical difference beginners notice most is energy use. Proof-of-work mining consumes large amounts of electricity because it relies on raw computing power, while proof-of-stake networks use a small fraction of that energy since they do not require solving energy-intensive puzzles.
Frequently Asked Questions
Which system is more secure?
Both have a long track record of security when implemented well. Proof of work has been tested longer through Bitcoin, while proof of stake has matured significantly and now secures major networks including Ethereum.
Why did Ethereum switch from proof of work to proof of stake?
The switch, known as "The Merge," was done primarily to reduce energy consumption dramatically while maintaining network security through a different incentive structure.
