How does POS(Proof of Stake) work ?

POS (proof of stake) is another consensus mechanism like POW that helps blockchain network reach an agreement.

POS algorithm selects the creator of the next block depending multiple mechanisms immensely depending on how they much their stake is in the blockchain.Participants in the network must have a certain stake in network for example by placing a amount in the network’s currency wallet connected to its blockchain.This process is known as placing a stake or “staking”.A creator of block is limited by his stake in the network, more his stake in the network the more chances he will be chosen as creator of the block. POS networks are based on deterministic algorithms immensely depending on his amount of stake but there are also different elements that define the selection of the next creator of the block. Otherwise , it could lead a too much centralized blockchain where only the rich would benefit.One of the other factor is the number of coins held in the wallet multiplied by the number of days they have been in that wallet.

About the 51% attack on POS is theoretically possible but practically not.Let me explain for the attacker he has to purchase 51 percent of the cryptocurrency in the market that is in circulation. Only way that would happen would is that they would buy from open market and everybody would realize what is happening , the network will realize what would happen and they would loose all their stake.

POS is considered the best alternative to POW which runs bitcoin.Ethereum a major blockchain network is moving towards Proof of Stake too.As POW requires huge amount of energy and impacts enviornment in negative ways.Whereas POS is looked as greener alternative and also a faster one.The networks on POS boost about their transactions per seconds and how less energy intensive they are .