Nodes are the backbone of a blockchain network. They store, validate, and relay transactions, ensuring decentralization and security. Each node is a computer connected to the blockchain network, helping maintain its integrity.

Types of Nodes in Blockchain

1. Full Nodes

   • Store a complete copy of the blockchain.
   • Validate and verify all transactions.
   • Participate in consensus mechanisms.
   • Example: Bitcoin and Ethereum full nodes.

2. Light Nodes (SPV Nodes)

   • Do not store the full blockchain.
   • Only download block headers to verify transactions.
   • Useful for mobile wallets and lightweight applications.

3. Mining Nodes

   • Solve cryptographic puzzles (Proof of Work) to validate transactions.
   • Compete to add new blocks to the chain.
   • Receive rewards (like Bitcoin miners).

4. Validator Nodes

   • Used in Proof of Stake (PoS) systems instead of mining.
   • Stake cryptocurrency to participate in transaction validation.
   • Example: Ethereum 2.0 validators.

5. Masternodes

   • Perform additional functions like governance and instant transactions.
   • Do not mine new blocks but help with network operations.
   • Example: Dash cryptocurrency uses masternodes.

6. Archive Nodes

   • Store the full history of the blockchain, including old transaction data.
   • Useful for historical analysis and auditing.

Functions of Nodes in a Blockchain

• Transaction Validation – Nodes verify transactions before adding them to the blockchain.
• Decentralization – Nodes distribute the network to prevent single points of failure.
• Security & Integrity – Nodes ensure data cannot be altered or tampered with.
• Consensus Participation – Some nodes help reach agreement on valid transactions.
• Data Storage – Full nodes store copies of the blockchain ledger.

Conclusion

Nodes keep the blockchain decentralized, secure, and transparent. Different types of nodes serve different functions, from storing data to validating transactions and securing the network.