In the blockchain network, nodes are the basic units that maintain the operation of the system, but not all nodes perform the same function. Full Node and Light Node, as two mainstream node forms, have designed differentiated technical architectures for different usage scenarios. The former is like the "complete ledger guardian" of the network, while the latter is a "lightweight verification assistant". How do they balance decentralization and efficiency? And which application scenarios are they suitable for?
Core concepts and technical differences
The full node stores the complete ledger data of the blockchain from the genesis block to the present, including every transaction record and block information. Its core features include:
- Data integrity : Download and synchronize the entire blockchain data (such as Bitcoin full node data has exceeded 400GB), verify the legitimacy of all transactions in real time, and ensure the consistency of the ledger;
- Independent verification capability : without relying on other nodes, it can independently verify whether there is double spending (repeated spending) and whether the balance is sufficient through the local ledger, which is the cornerstone of blockchain decentralized trust;
- High hardware requirements : high-performance servers, large-capacity storage and stable networks are needed, suitable for long-term operation and maintenance, such as the Bitcoin network with about 15,000 full nodes supporting global transaction verification.
Light nodes do not store the complete ledger, only retaining block headers (including hash values, timestamps, and other metadata). Transaction verification is implemented through the "Simplified Payment Verification (SPV) " Technology. The core features include:
- Lightweight data : the storage capacity is only one ten thousandth of the full node (such as Bitcoin light node only needs a few MB of space), which can run on mobile phones and embedded devices;
- Relying on full nodes : When verifying transactions, it is necessary to request Merkle branch data containing the target transaction from the full node, and confirm the existence of the transaction through hash verification, rather than verifying all transactions;
- Convenience first : sacrificing some independence for low resource consumption, suitable for scenarios with high portability requirements, such as blockchain wallets and IoT devices.
Dimension
Full node
Light node
Data storage
Complete ledger (GB level)
Only block header (KB level)
Verification method
Independently verify all transactions
Relying on full nodes to provide Merkle proofs
Hardware requirements
High (server level)
Low (mobile phones/embedded devices)
Degree of decentralization
High (independently maintained ledger)
(Depends on full-node network)
Applicable scenarios
Cyber security core support
Lightweight interaction for end users
Application scenarios and role positioning
- Full nodes: the core pillar of cyber security
- Public chain infrastructure : Bitcoin, Ethereum and other public chains rely on full node networks to maintain decentralization, and each full node independently verifies blocks to prevent malicious attacks. For example, Ethereum full nodes run through Geth Client, synchronizing about 10TB of ledger data in real time to ensure the correctness of smart contract execution.
- Compliance platform underlying support : [HashKey Exchange] and other compliance trading platforms deploy full nodes to monitor the flow of assets on the chain in real time, independently verify the legality of user recharge and withdrawal through the local ledger, and comply with Anti Money Laundering (AML) and customer identification (KYC) regulatory requirements;
- Enterprise-level consortium chain : In the financial, government and other consortium chains, the full node is operated by institutional members to jointly maintain the shared ledger, such as the full node of the interbank clearing chain to ensure real-time synchronization and compliance audit of cross-border transfer data.
- Light nodes: the efficiency choice for end users
- Mobile end blockchain wallet : MetaMask, Trust Wallet and other light wallets adopt light node architecture. Users can send and receive cryptocurrency without downloading the complete ledger. By requesting Merkle proof from the full node, transactions can be quickly verified to improve the mobile end user experience.
- Internet of Things (IoT) devices : Deploy lightweight nodes in resource-constrained sensors and smart home appliances to achieve low-power blockchain interaction. For example, in a supply chain traceability project, logistics equipment verifies commodity circulation records through lightweight nodes without consuming a lot of computing power.
- Cross-chain bridging and data aggregation : Lightweight nodes can serve as "lightweight gateways" for cross-chain communication, such as the lightweight nodes in the Polkadot ecosystem that quickly verify the block header information of parallel chains, reducing the resource consumption of cross-chain data interaction.
Full nodes and light nodes are not opposed, but form complementary ecosystems.
- When a light node initiates a transaction, the full node is responsible for broadcasting and deep verification throughout the network to ensure that the transaction is legally packaged.
- Full nodes expand network coverage through the widespread deployment of light nodes, which rely on the complete ledger of full nodes for fast verification. Together, they support the balance of "decentralization + efficiency" in the blockchain network.
Challenges and future trends
Full nodes face the problems of storage expansion (such as Bitcoin's annual increase of about 100GB) and high operating costs, while light nodes face the risk of centralization of verification dependencies (such as excessive reliance on a few full nodes). Technological evolution is driving the integration of the two: full nodes reduce the storage pressure of individual nodes through sharding technology (such as Ethereum sharding); light nodes use zero-knowledge proofs (Zk-SNARKs) to enhance verification independence and reduce dependence on full nodes.