The info graphic shows the flow in `What is iroh?`, and quickly looking at the endpoint area you can see what the key is: https://docs.iroh.computer/connecting/creating-endpoint#pers...

It might be the docs just mesh with how I think about things. The creators should expand on this, since people seem to not mesh with the current info.

They mention later on it's an Ed25519 key.

It seems to use DHT under the hood whether directly or through a relay. https://pkdns.net/ .

That is a pluggable/possible, but non-default, configuration.

I suggest going through https://www.youtube.com/watch?v=RwAt36Xe3UI for an explainer.