The Lightning Network is a layer 2 payment protocol that operates on top of a blockchain-based cryptocurrency. It is intended to enable fast transactions amongst participating nodes and has been proposed as a solution to address bitcoin scalability problem.

Transactions between parties will be executed off the Blockchain i.e. as off chain transactions. It will reduce transaction processing times and associated costs. Thaddeus Dryja and Joseph Poon formulated Bitcoin Lightning Network in 2015.