Don on Nostr: What on earth is pupkey?

{ "id": "62aa8e1b0a5d3fba98bf15075424a45ffdb509f342f3eeba64cb5fb75c58285f", "pubkey": "db8301f090eaa6c7f2cc2ec50858e81a43e5b6e95b303847a2e16091de7d87fc", "created_at": 1714145251, "kind": 1, "tags": [], "content": "What on earth is pupkey?", "sig": "4045c6c062fca01730d1ce9a1f919003c1886f2eabf615eba975117f2780b5baea6ee079bae03ffaf54ba8e14d18c44039bf3fffb6e7a16f511f18b0949c882d" }