Proof-of-Work (PoW) is a consensus algorithm that is used to create distributed trustless systems. In a Proof-of-Work system, participants compete against each other to solve complex mathematical puzzles in order to approve transactions or blocks in the blockchain.
As such, Proof-of-Work is an essential protocol for the secure operation of distributed ledgers. Proof-of-Work systems require that miners use their computing power to solve mathematical puzzles in order to approve transactions and blocks.
These mathematical problems are designed to be difficult to solve, but easy to verify in order to prevent fraud. Once a miner has solved the puzzle, they are rewarded with a reward, usually in the form of cryptocurrency tokens. As each puzzle must be solved individually, this process results in a large amount of computing power being used to maintain network security.
In addition to providing security, Proof-of-Work also protects against censorship since miners must expend energy in order to approve transactions and blocks. If a miner is prevented from solving the puzzle by an outside force, they will not be able to receive any rewards.
This makes Proof-of-Work ideally suited for distributed systems that need to be secure and resilient against attack while also offering incentives for users who offer their computing power to the network.