Crypto glossary
Nostr
Nostr is an open, censorship-resistant protocol for social messaging in which identities are key pairs and posts are relayed by independent servers.
Nostr, short for 'notes and other stuff transmitted by relays', is deliberately simple. A user's identity is a public key, often shown as an npub address, and every post or 'event' is signed with the matching private key. Clients send events to any number of relays, which are simple servers that store and forward them. Readers fetch from whichever relays they choose and verify signatures themselves, so no single relay can impersonate or permanently silence a user.
The protocol has strong ties to the Bitcoin community: 'zaps' are Lightning Network tips attached to posts, and Jack Dorsey funded early development. Apps such as Damus and Primal built social clients on it, but Nostr is also used for marketplaces, long-form writing and wallet connections.
Because there is no account recovery, losing the private key means losing the identity, and pasting it into many apps is risky. Relays can still refuse content, spam filtering is up to clients, and the user base is small compared with mainstream networks.
Example
A journalist banned from a mainstream platform posts from her Nostr key; even if two relays drop her posts, followers still see them through the other relays her client publishes to.