Would say your understanding is correct. It uses something similar to a "gossip" protocol where the public keys of other users are advertised.
So it gets ride of IP addresses and can jump boundaries between different network types. I'm using it for BLE to BLE communication, I've seen videos of people using it for USB to USB communication. There aren't many limitations as long as data can flow.
> I've seen videos of people using it for USB to USB communication.
How would that work? Do you have a link?