Blockchain miners

Blockchain miners and blockchain validators (see the upcoming sections) both have to do with consensus, which will be explored in depth in Chapter 7, Achieving Consensus. Generally, blockchain miners are associated with blockchains. A PoW chain functions by having the computers that are miners compete to do the work needed to certify a block in the chain. Currently, the only major PoW blockchains are Bitcoin, Litecoin, and Ethereum. Most other systems use a variation of  PoS consensus, which we will discuss in the next Blockchain validators section. We'll cover how mining works in detail in Chapter 18, Mining.