A decentralized layer-2 protocol built on top of Bitcoin that uses a peer-to-peer network of payment channels to enable cheaper, faster, and more scalable transactions. Payments on Lightning are aggregated off-chain and then sent to the Bitcoin mainchain for final settlement, leveraging Bitcoin’s security and decentralization while improving transaction throughput and helping Bitcoin scale globally.
Lightning is a scaling solution for Bitcoin. Because Lightning payments settle off-chain within each channel, the network's aggregate capacity scales with the number of open channels rather than Bitcoin's block size; each channel can carry up to 483 HTLCs, or in-flight payment attempts, at once under BOLT 2, though no official network-wide throughput figure has been measured or published. VISA, by comparison, processes more than 320 billion transactions a year and up to 83,000 transaction messages per second at peak.