What is a Bitcoin Node and why should everyone understand it?

In the world of distributed networks, the term “节点” (Node) is often mentioned. Simply put, a node is a communication point in the network - it can create, receive, or forward information. In the Bitcoin ecosystem, the role of nodes is even more crucial.

Why Does Bitcoin Need Nodes?

The reason why Bitcoin can become a truly decentralized P2P digital currency lies in its node network. It is this globally distributed computer node network that allows Bitcoin to operate without any intermediary institutions. Each device connected to the Bitcoin network essentially acts as a node. These nodes communicate with each other through P2P network protocols, ensuring that transaction information and block data are propagated and verified throughout the network.

Each type of Node has its responsibilities

Complete Verification Node - Guardian of the Network

Full nodes are the backbone of the Bitcoin network. These nodes download and store a complete copy of the blockchain, verifying each transaction and block to ensure they comply with the system's consensus rules. In other words, full nodes are constantly checking “Is anyone cheating?”.

To run a full Node, you need to prepare:

• Computers running Windows, Mac OS X, or Linux operating systems
• At least 200GB of available disk space
• 2GB RAM
• High-speed internet connection with an upload speed of at least 50 kB/s
• It is recommended to run for at least 6 hours a day, preferably 24/7.

According to statistics, by 2018, there were about 9,700 publicly listed listening nodes on the Bitcoin network. But this number is just the tip of the iceberg—there are many hidden nodes operating behind firewalls or through privacy protocols like Tor, and they also contribute to maintaining the security of the network.

Super Node——Data Transfer Station

Super nodes (also known as listening nodes) are essentially publicly visible full nodes. They run 24/7, maintaining multiple stable connections and continuously transmitting blockchain history and transaction data to other nodes around the world. This means that super nodes require more powerful computing capabilities and better network connections.

Miner Node - Competitive Participant

To mine and earn Bitcoin, miners must invest in specialized mining hardware and software. These mining programs run in parallel with Bitcoin Core, aiming to find valid Bitcoin blocks. Miners can choose to mine alone (solo-miner) or join a mining pool (pool-miner). In a mining pool, only the pool administrator needs to run a full Node, while other miners contribute their computing power.

Light Client - Lightweight Participants

Light clients (SPV clients, short for Simplified Payment Verification) can use the Bitcoin network without downloading the entire blockchain. These types of nodes do not maintain a complete copy of the blockchain and do not participate in the process of verifying and confirming transactions, thus their contribution to network security is limited. However, many cryptocurrency wallets are designed based on this type of light client because it is more resource-efficient.

Node vs. Miner - Don't Confuse Them

There is a common misconception: running a full node ≠ mining. Anyone can run a full validation node, but only miners with specialized hardware can participate in the mining competition. Miners must collect pending transactions (which have been verified as valid by full nodes), package them into candidate blocks, and then attempt to find a valid solution for this block. Once successful, miners broadcast the new block to the network, where it is validated for its validity by other full nodes. Therefore, it is the distributed network of validation nodes that truly maintains the consensus rules, not the miners.

Why Running a Full Node is Important

Although running a full validating node does not have direct economic returns, it provides users with real value: trust, security, and complete autonomy.

Full nodes can:

• Verify that all rules are being followed
• Protect the blockchain from attacks and fraud (such as double spending attacks)
• Allow users to have full control over their funds without relying on third parties.

This is exactly the original intention of Bitcoin's design - a decentralized system that anyone can participate in and anyone can verify. Through the P2P network protocol, all nodes communicate with each other, and once a node behaves improperly or attempts to spread false information, honest nodes will quickly identify and isolate it.

Therefore, establishing a more decentralized Node network is crucial for the health and security of the entire Bitcoin ecosystem.