Proof of Work [PoW]

PoW is the original consensus algorithm in a blockchain network. In a PoW algorithm, the miners compete against each other to validate a block and the first miner who presents validation for a block gets rewarded. For example, a miner repeatedly inserts transaction data (block) and a random string of digits (nonce of block) into a hashing formula, until the miner finds a desirable outcome – the PoW. Other miners can verify the PoW by taking the alleged input string and applying it to the same formula to see if the outcome is what the initial minor presented. Some view PoW as a controversial consensus algorithm because of the electricity costs involved in performing the formula calculations.