Lightning Network is a peer-to-peer payment network that runs on top of the Bitcoin Blockchain. Because it runs on top of the Blockchain it is called a layer-two solution, which groups it together with other solutions that have this property of being built on top of a Blockchain. Layer One is the base layer, where the Blockchain lives. Because of the inherent properties of Layer One, it is impossible to process large amounts of transactions in that layer. The Bitcoin Blockchain can famously process a mere seven transactions per second on average. This constraint was the main impetus for the creation of Layer Two solutions. Lightning Network, being a Layer Two solution, allows for near instant transactions, that can easily scale to millions of transactions per second.