What is Light Client?

A light client is a type of blockchain node that allows users to interact with the blockchain network without having to download and store the entire blockchain data.

Light clients download and verify only the block headers instead of the full blocks and transaction data. This makes them lightweight and suitable for devices with limited storage and computing resources like mobile phones and IoT devices. They rely on full nodes to request specific transaction data and Merkle proofs when needed. The light client can then verify this data against the block headers it has downloaded.

Benefits of Light Client

• Enabling wider participation and decentralization: Light clients allow devices with limited resources like mobile phones, IoT devices, and browsers to interact with the blockchain network securely without running a full node. This promotes greater decentralization by allowing more participants to verify transactions and data.
• Scalability: Running a full node requires significant storage, bandwidth, and computing power to store the entire blockchain data and process all transactions. Light clients overcome this barrier by only downloading and verifying the essential data like block headers, enabling scalability for the network.
• Trust minimization: Light clients do not blindly trust full nodes. Instead, they cryptographically verify the data received from multiple full nodes using techniques like Simplified Payment Verification (SPV) and fraud proofs. This allows users to trustlessly interact with the blockchain.
• Cross-chain interoperability: Light clients are crucial for enabling secure cross-chain communication and bridges between different blockchain networks. They allow smart contracts on one chain to verify data from another chain without running a full node of that chain.
• Mobile and browser wallets: Light client protocols are essential for building secure and user-friendly mobile and browser wallets that can verify transactions and balances without storing the entire blockchain.