Proof of Work (PoW) is a consensus algorithm used by blockchain networks to reach distributed consensus. It is a cryptographic algorithm that relies on miners computing hashes to form a blockchain. With PoW, miners compete to solve complex mathematical problems in order to add new blocks to the chain and collect rewards for their efforts. All miners must solve the same problem in the same amount of time to remain competitive, and those that complete the puzzles first get rewarded with cryptocurrency.