The Lightning Network (LN) is a rapidly growing second-layer payment protocol that works on top of Bitcoin to provide near-instantaneous transactions between two parties. This book examines: How the Lightning Network addresses the challenge of blockchain scaling The Basis of Lightning Technology (BOLT) standards documents The five layers of the Lightning Network Protocol Suite LN basics, including wallets, nodes, and how to operate one Lightning payment channels, onion routing, and gossip protocol Finding paths across payment channels to transport Bitcoin off-chain from sender to recipient.