What is a Node/Validator

“Validators” (also known as “validation nodes”) are responsible for verifying on-chain transactions. When a transaction is successfully validated, the validator adds it to the distributed ledger.

Generally, validators receive token rewards as an incentive for their “validation work.” Conversely, validators that engage in misconduct will be penalized (usually temporarily or permanently barred from participating in the system).

The number of validators varies depending on the blockchain. Additionally, the types of validators differ based on the consensus mechanism used. Here, we will only introduce the two most common types of validators in the consensus mechanisms.

Validators in the PoW Consensus Mechanism

In networks based on the PoW consensus mechanism, such as Bitcoin, validators are called miners. They earn the right to validate transactions by solving complex computational problems. Their rewards are based on their “work.”

What is PoW? How does the PoW consensus mechanism work? Please refer to the sections “What is a Consensus Mechanism” and “What is Proof of Work.”

Validators in the PoS Consensus Mechanism

In networks based on the PoS consensus mechanism, such as Solana, Ethereum 2.0, Avalanche, etc., participants need to stake a certain amount of the network’s native tokens to become validators. Validators who correctly participate in the validation process will earn rewards. The detailed reward rules vary by network.

What is PoS? How does the PoS consensus mechanism work? Please refer to the sections “What is a Consensus Mechanism” and “What is Proof of Stake.”

Node vs. Validator

Nodes in a blockchain network are divided into three categories:

Light nodes

Full nodes

Archive nodes

As the name suggests, light nodes only download block headers, not entire blocks. This reduced requirement allows users to interact with the blockchain network without powerful hardware or high bandwidth. However, light nodes do not participate in the consensus process, meaning they cannot act as miners or validators.

On the other hand, full nodes actively participate in block validation and verify all blocks and states. Although, in theory, full nodes store the entire blockchain data, they usually cache only recent data for faster access. For example, Ethereum full nodes only retain the most recent 128 blocks.

Archive nodes have the same functions as full nodes but also archive all historical state data. This feature allows users to query the state of the blockchain at a specific point in time directly, without having to derive it from current data. While archive nodes can participate in block validation, they are not obligated to do so. **$NOT **