In a blockchain network, nodes are essential components that perform several critical functions to maintain the network's integrity, security, and functionality. Here's a detailed explanation of what nodes do in a blockchain:
1. Transaction Validation
Nodes are responsible for validating transactions. When a transaction is initiated, it is broadcast to the network where nodes verify the transaction's legitimacy. This includes checking whether the digital signatures are valid and whether the transaction initiator has sufficient balance to complete the transaction[1][11].
2. Block Validation
After transactions are validated, they are grouped into blocks. Nodes then perform the task of validating these blocks to ensure they adhere to the network's rules. This process involves checking the block's hash to ensure it meets the required format and confirming that all transactions within the block are valid and not duplicated elsewhere[3][11].
3. Consensus Participation
Nodes participate in the consensus process, which is the method used to agree on the validity of blocks. Different blockchain networks use various consensus mechanisms like Proof of Work (PoW), Proof of Stake (PoS), or others. Nodes contribute to this process to agree on the state of the ledger and to prevent double-spending[3][11].
4. Maintaining the Blockchain Ledger
Nodes store and maintain a copy of the blockchain ledger. Full nodes keep a complete copy of the blockchain, which allows them to fully validate blocks and transactions independently. Light nodes, on the other hand, store only part of the blockchain and rely on full nodes for complete transaction validation[1][3].
5. Broadcasting Information
Nodes also play a crucial role in broadcasting new transactions and blocks to other nodes. This ensures that all nodes in the network are updated with the latest state of the blockchain ledger. By continuously receiving and transmitting data, nodes help maintain the blockchain's decentralized nature[1][11].
