The nuclear device requires at least an atomic device to detonate, whereas an atomic device doesn’t require either an atomic nor nuclear device to detonate.
Yields are also different by several orders of magnitude for the critical mass utilized.
I’m not a nuclear scientist, but I stayed at a Holiday Inn in Los Alamos last night. <;^)
I looked it up before my original post to prevent just such discussion as we are engaged. I have no problem with my post as I’m confirmed by what I read on line about atomic, and nuclear so I will sleep tonight in spite of it all.
I caught your humorous comment, and appreciate it, but apparently some wish to be entirely too technical when the meaning of it all is clear, and need no such discussion.