What is Nostr?

Public Key
npub13tttr58dg4n8hvymgwcr4xnww46u5vhmnd6n6lxjp95ulnzyyzqslclm0z
Profile Code
nprofile1qqsg44436rk52enmkzd58vp6nfh82aw2xtaekafa0nfqj6w0e3zzpqgyqeer5
Author Public Key
npub13tttr58dg4n8hvymgwcr4xnww46u5vhmnd6n6lxjp95ulnzyyzqslclm0z