Neither, really, it’s just that "public domain" is a US-specific legal term that doesn’t have equivalents in most countries. For one example, in Sweden you can

Neither, really, it’s just that "public domain" is a US-specific legal term that doesn’t have equivalents in most countries. For one example, in Sweden you can never fully sign away the right to have creative work attributed to your name (until 50/70 years after creation/creator death, depending on nature of the work) as a creator. You can make a pinky promise to not claim that right, but you can’t fully waive it so you could always have a change of heart and demand to be credited by name later. IIRC this came from a notion of protecting artists and photographers from predatory contracts from the print industry or something similar. Commercial rights etc can all be fully transferred, of course.