#Nostr101 "npub" is your public key. It never changes. "nprofile" has both your public key and your current home relay. It changes as your outbox relay list changes. When you are sharing your user, prefer to share it as an nprofile since the receiving user / app can quickly figure out where to get more information from the user. If the receiving app only has the npub, it has to search for a relay that has the user. If the receiver is using the same relays as the sender, that's easy. But if the receiver is on a separate relay set, then it's likely the receiver will never load the user. Outbox model fixes this but it requires you to share the nprofile, not just the npub.