Lightning Network

The Lightning Network is Bitcoin's primary scaling solution for fast, cheap payments. Instead of every transaction landing on the base blockchain, two parties open a payment channel by co-signing a funding transaction, then update balances between themselves off-chain by exchanging signed messages. Only the opening and eventual closing of the channel touch the main Bitcoin blockchain; everything in between is instant and effectively free.

The network extends this to routing: a payment from A to C can hop through intermediary B (or any longer chain of nodes) using HTLC constructions, so users do not need a direct channel with every payee. The result is a payment network with sub-second settlement and sub-cent fees for small payments — a very different experience from on-chain Bitcoin's minute-to-hour confirmations.

The trade-off is liquidity management: nodes need funded channels to route, and channels need enough capacity in the right direction to move the payment. For end users this is invisible on well-maintained wallets, but the underlying accounting is more complex than on-chain Bitcoin. Lightning excels at small, frequent payments (tips, retail purchases, streaming payments); it is less common for large or one-off value transfers, where on-chain Bitcoin remains the default.