Will a Lightning Network have its own blockchain?
No, Lightning is dependent on the bitcoin blockchain. On-chain transactions is needed to open and to close “channels” between peers in the network.
Once a channel is open, the ownership of bitcoin can be transferred off-chain in both directions.
The transactions inside a channel are real bitcoin transactions, but they are not broadcasted to the bitcoin network as long as the channel stays open.
Instead, participants of the channel will store the transactions locally.
This enables instant transactions and a near unlimited capacity within a Lightning Network.