What do bitcoin nodes have to do with lightning? I am just trying to understand how this works.

#[5] just told you. What part are you seeking clarification on?

#[6]

A bitcoin node that runs the Lightning Network protocol creares timelocked multisig transactions called channels using bitcoin to enable very low or even no-fee forwarding of payments between peers. The transactions have immediate final settlement, can be withdrawn and spent, and when the channel is closed, the transaction is broadcasted to the bitcoin blockchain. There is no token used other than satoshis, the smallest units of bitcoin.