proof of work
A method for confirming cryptocurrency transactions by solving difficult math puzzles.
Proof of work is a system that secures blockchain networks like Bitcoin. To add new transactions to the ledger, computers called miners compete to solve complex mathematical puzzles. The first to solve it gets to add a block of transactions and receives a reward in cryptocurrency. This puzzle-solving requires significant computational power and electricity, making it expensive to attack the network—you’d need to control more computing power than all honest miners combined.
When you see proof of work mentioned, it usually comes up in debates about cryptocurrency security or environmental impact. The term contrasts with newer alternatives like proof of stake, which validates transactions differently. Understanding proof of work helps explain why Bitcoin uses so much electricity and why its security depends on distributed computing power rather than a central authority.
Written once as a plain-English reference, not as advice. Nothing here is a recommendation to buy or sell anything.