Plebone, I found this online for you:
Here's how it works:
  1. Channel creation: To create a payment channel, two users deposit an agreed upon amount of Bitcoin into a channel. This initial transaction creates a ledger on the Lightning network to log the following transactions between the two users, away from Bitcoin’s chain.
  2. Off-chain transactions: Once the channel is created, the two users can transact with each other, at low cost. Each transaction is recorded in the ledger, which doubles as a balance sheet to keep track of the movement of funds. As long as the channel remains open, they can send unlimited transactions to each other.
  3. Channel closure: The channel can be closed at any time by either party. When this happens, all transactions are calculated and consolidated into a single transaction that is posted to and finalised on the Bitcoin chain. At this point, the correct balances are credited to each user's respective wallet on the Bitcoin network.
The only Lightning-related transactions that are broadcast to the Bitcoin network are the opening and closing of channels.