Proof of Work (PoW) is a consensus algorithm that requires participants (miners) to solve cryptographic puzzles to validate transactions and create new blocks on a blockchain. The process of solving these puzzles consumes computational power and energy, making it costly and time-consuming. This mechanism is primarily used to prevent malicious activities such as double-spending and to secure the network against attacks. The first miner to solve the puzzle adds a new block to the blockchain and is rewarded with cryptocurrency, typically in the form of the native coin of the network they are mining.