Blockchain distributed ledgers work by linking together a chain of electronic records, each inextricably tied to the one before it; each new set of entries or "blocks" is completed and time-stamped with a hashtag only after passing through a consensus process.The two most popular mechanisms or protocols for authenticating new entries on a blockchain and governing changes to the networks are Proof of Work (PoW) and Proof of Stake (PoS).[ Further reading: Bitcoin mining leads to an unexpected GPU gold rush ]As the name suggests, PoS consensus models enable those with the most digital coins (the greatest stake) to govern a cryptocurrency or business blockchain ledger.
To date, however, the most popular blockchain-based cryptocurrencies & Bitcoin, Ethereum (Ether) and Litecoin & have used PoW as their consensus mechanism.