Proof of work (Proof of Work, PoW) is the best-known system of organizing mining, in which the reward depends directly on the computational work performed. Network nodes compete for the right to add a new block by solving a resource-intensive computational task — finding a hash that satisfies a given condition.

Since the hashing process has a parameter such as difficulty, changing it constantly adjusts the required hardware performance. The network automatically tunes the difficulty to maintain a stable interval at which new blocks appear, regardless of the total power of the participants. Thus, a miner's reward is determined by the work actually performed: the more computing resources they invest, the higher their chance of finding a block.

Features of Proof of Work

• High resistance to attacks due to the costliness of computations;
• A transparent and verifiable link between the reward and the work done;
• Significant energy consumption and the need for specialized hardware;
• Automatic adjustment of the network's difficulty.

Proof of Work underlies a number of the first and best-known cryptocurrencies. The algorithm's main trade-off is considered to be its high energy consumption, which became one of the reasons for the emergence of alternative mechanisms, for example Proof of Stake.