kup on Nostr: What are they?

{ "id": "0025f37090bd6ebcb36cad396639192fd93159a793d8fb8a61edbfeb6c7ef4be", "pubkey": "671597832fb8337c868e78d9dcacab0d2801b01f2beefb489febec229f87abea", "created_at": 1736825131, "kind": 1, "tags": [ [ "e", "f11cb6844ed48b56cfba6cc1354f0fdcb25aed316acc1b57340dedaa7354c16e", "", "root" ], [ "p", "61066504617ee79387021e18c89fb79d1ddbc3e7bff19cf2298f40466f8715e9" ] ], "content": "What are they?", "sig": "f8d6075db9ca11b0aff7d2ae9b34a8a63c3ee71779ab211b48f16dff34c1a41b72d033951952bda59932de8651c2c09b4b3c48aae6b5753a89dfedca1c809f6c" }