Lightning Network

The Lightning Network is Bitcoin’s primary payment-scaling layer. Two parties open a channel by locking BTC in an on-chain multisig; transfers between them then happen off-chain with cryptographic settlement guarantees, and only opening and closing transactions touch the Bitcoin base layer.

Lightning is the closest thing Bitcoin has to a high-throughput retail payments rail, used by exchanges, custodians, and direct end-users worldwide. Its protocol is implemented by multiple independent node software stacks (LND, Core Lightning, Eclair).