A blockchain validator is someone who is responsible for verifying transactions on a blockchain. Once transactions are verified, they are added to the distributed ledger.
In proof-of-work (POW) systems like Bitcoin, validators, also known as miners, solve complex computational math problems in order to win the right to verify transactions and receive rewards for the “work.” This is the original method of confirming transactions on the blockchain. POW requires each node in the Bitcoin network to solve a problem. The first node that solves the problem is granted permission to add a new block and the miners are awarded bitcoin for their work. The nodes are the administrative body of the blockchain and verify the legitimacy of the transactions in each block. Once a block of transactions has been verified, the data is written into the blockchain.
In proof-of-stake (POS) systems like Avalanche, validators are given rewards as long as they stake the network’s token and correctly participate in the network. This mechanism helps secure the network by imposing the need to lock up value in the network in order to participate in the consensus decisions. The Proof of Stake (PoS) concept states that a person can mine or validate block transactions according to how many coins they hold. This means that the more coins owned by a miner, the more mining power they have.