Guys, this is something you definitely need to understand: the Lightning Network!
When a channel is closed, the final balance is settled on the Bitcoin main chain through an on-chain transaction.
The core idea of the Lightning Network is to move large numbers of small, frequent payments off-chain. Only opening and closing channels happen on-chain, which eases the burden on the main chain and reduces fees.
$BTC also circulates on the Lightning Network; most payments just don't need to be recorded on-chain individually.
Save this and take your time reading it.