Nostr: a quick introduction, attempt #3
Nostr is a description of a message format called "event" that is cryptographically signed and the description of public communication interface that can be offered by servers called "relays".
Armed with such two descriptions anyone can write programs called "clients" that run on people's computers and can send and receive "events" to and from the "relays".
Some people, once they learn this, start thinking of Nostr as a set of free that are readable and writable by everyone.
From that may come questions such as: "who will run these relays?"; or concerns like: "how can this be censorship-resistant if you can just take down the relays?".
Don't be one of these people.
Nostr is not any specific set of relays, and relays are not meant to be public or free. Remember from the first paragraph above: Nostr is just a description of an interface. What does that mean? It means that if you send a message to a relay saying hello mr relay please send me the messages you have it will not understand that message and will probably ignore you. But if you send a message like ["REQ", "z", {"limit":10}] then it will understand and will send you 10 events.
There are other types of messages relays will understand, but that is basically all that there is to it.
If a relay will be free or not that depends on what the program running on the relay server decides to do.
If a relay will store your event specifically that depends on what the program running on the relay server decides to do.
If a relay will delete your event after a while or store it in 32 redundant copies that depends on what the program running on the relay server decides to do.
If a relay will allow anyone to read any event they might have or if they will only allow some people to do that it will depend on... you get the idea.