Bitcoin lightning off-chain (layer2) so that Bitcoin transactions are not recorded (not need to be mined and those fast TPS.)
layer2 lightning is just nodes that run lightning software
you can open a Lightning channel by depositing bitcoin in multi-sig address so that this transaction is recorded on blockchain.
after that you get bidirectional payment channel or you can Routing your payment Over Lightning.
when you close your channel that balance of that multi-sig address change with your last balance update/