Proof of Work

Proof of Work is a system that secures cryptocurrency networks by requiring computers to solve difficult math puzzles before adding new transactions to the blockchain (a shared ledger). The first computer to solve the puzzle gets to record the next batch of transactions and earns new cryptocurrency as a reward. This process, called mining, makes it extremely expensive and time-consuming for anyone to cheat the system—they'd need to control more computing power than the rest of the network combined. Bitcoin uses Proof of Work, which is why Bitcoin mining consumes so much electricity. It's the original way cryptocurrencies solved the problem of "who decides what's real?" without needing a bank in the middle.