So, Damus is the app. Note is the publications. And Nostr is the network. Got it. 👍
Discussion
Relays are the network. Nostr is the protocol.
So as of now there are only 4 different relays?
You can add more. I have 21 but people say more than 15 starts to cause some performance.
Issues*
Here is a fairly large list of relays:
Damus is one of many many apps. It's only available on apple devices so far.
Note is basically our "tweet." It could be anything from a video to a blog post to a music stream though, we're far more flexible here than twitter is.
Nostr is most definitely the network. It allows you to bring your list of follows & followers around with you to any app on the network. I highly recommend you try other apps to see how wildly they vary from each other.
Welcome!
You check out https://nostr.how for more info too. :)