To confuse things further, there is DSD-wide and DXD, which are mulit-bit formats (8 bits I think) at high rates, used for editing DSD. Those formats are pretty much high sample rate and lower bit-depth PCM as far as I'm aware, providing large bandwith for converted 1-bit DSD information to fit comfortably, including the frequency-shifted noise. Similar transitional format manipulation goes on within the ADC/DAC depending on the implementation, or so I've read.
The basic information theory thing is number of bits verses sample rate, slice it how ever you want as long as it adds up (or mulitplies, rather) to provide the sufficient bandwith required. The devil is in the details of how to manipulate it, and in the conversion details to and from analog at each end.
Basic information theory and PCM is confusing enough for folks. DSD and it's complications seem to confuse everybody even more, without really doing away with the need for PCM (which thankfully isn't going anywhere regardless), so to me it just seems a needless waste of braincells and other resources IMHO. I sometimes think it was invented just to keep audiophiles arguing so they don't notice more important things that really matter. But I know it was really just basic human greed that motivated it, cloaked in false claims (thanks Sony).
I think we're getting close to Texas now. This certainly isn't Kansas anymore, Toto. Carry on my wayward sons and don't let the radiator boil over..