The Lightning Network is a payment network designed to enable fast and low-cost Bitcoin transactions. Bitcoin was originally created as a secure and decentralized monetary system. However, recording every transaction directly on the blockchain presents limitations in speed and cost, especially for everyday small payments. To address this, Lightning was designed as a Layer 2 network built on top of Bitcoin.
The core idea behind Lightning is simple. Instead of recording every transaction on the blockchain, two wallets open a payment channel and conduct multiple transactions off-chain. Only the final result is later settled on the Bitcoin blockchain. Through this structure, Lightning payments are completed within seconds, regardless of blockchain congestion. Importantly, Lightning does not replace Bitcoin—it preserves Bitcoin's security while significantly improving payment efficiency.