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The most popular networks — like Bitcoin or Ethereum — use<strong> Proof of Work</strong> <strong>(PoW) </strong>as such rule. <strong>Miners </strong>(validation nodes) provide operability of the whole blockchain network, and for this type of work, which is basically computing, they are ‘rewarded’ with a certain portion of an appropriate crypto. And the more miners there are within the PoW-based network the more complex computing has to be performed. Thus, eventually the network gets to the point, when it takes fairly long time to perform a computing operation.