What is Nostr?

I repost fake screenshots.
Public Key
npub1uf5zzt0qjau4u2449qcupemkgaum4ac248ankq0u62mkjlwz2utsu0pcq3
NIP-05 Address
blaaablaaaa_at_hermit.cafe@momostr.pink
Profile Code
nprofile1qqswy6pp9hsfw727926jsvwquamyw7d67u92n7emq87d9dmf0hp9w9cr7jha6
Author Public Key
npub1uf5zzt0qjau4u2449qcupemkgaum4ac248ankq0u62mkjlwz2utsu0pcq3