Proof of work is a consensus mechanism where miners compete to solve a computational puzzle to add a new block of transactions.
Miners run hardware that repeatedly guesses a value until it meets the network's difficulty target. The winner adds the block and earns a reward.
Because mining requires real energy and hardware, attacking the network is expensive, making it economically impractical.
Proof of work is extremely secure and battle-tested, but it consumes significant electricity and requires specialized hardware.
Bitcoin is the most famous proof-of-work network, along with a few others like Dogecoin and Litecoin.
Proof of work is the original and most proven consensus mechanism, trading energy efficiency for unmatched security.