What Is a Node?

A node is a computer or device connected to a blockchain network that plays a role in maintaining and verifying the distributed ledger. Nodes are essential to the network’s operation and come in different types depending on their function.

How It Works

1. Distributed Database: Each node holds a copy of the entire blockchain, which helps ensure that the network is decentralized and resilient to failure or attacks.
2. Verification: Nodes communicate with each other to validate new transactions and blocks. This ensures that all participants have a consistent version of the blockchain.
3. Types of Nodes:

• Full Node: Stores the entire blockchain and participates in transaction validation and block verification.
• Light Node: Holds only parts of the blockchain, focusing on specific tasks with fewer resources.
• Mining Node: Specifically set up to mine new blocks and earn rewards, usually participating in Proof of Work (PoW) systems.

Example

In the Bitcoin network, thousands of nodes are spread globally. Each node verifies incoming transactions and broadcasts them to other nodes, ensuring every new block added to the chain is legitimate and in sync with others.

Key Takeaways

• Decentralization: Nodes contribute to the decentralized nature of blockchains, making them secure and difficult to tamper with.
• Validation Role: Without nodes, there would be no mechanism to check or approve transactions on the blockchain.
• Different Types: Nodes can serve different roles, from storing full blockchain data to handling only specific tasks.

In short, nodes are like the backbone of blockchain networks, keeping them alive, accurate, and secure by communicating and sharing data with other nodes.