Since Bitcoin's blockchain can handle around seven transactions per second (TPS), the network's scalability eventually became an issue, and a second-layer solution was suggested called the Lightning Network (LN).
The LN solution enabled split-second Bitcoin transactions in high volumes between users without network confirmations. By opening Lightning channels "off-chain", users can transact between each other for infinity and settle only the final amount. LN transactions cost nearly nothing and allow sending the tiniest fractions of Bitcoin.