Viruses, and Viroid and Virusoids OH MY!!

I am compiling some statistics on these and I was wondering if anyone can shed some light on the “Delta Agent” of Hepititis D

It was explained to me that Viroids are RNA organisms and unlike the RNA Viruses the lack the protective protein coat. But they can exist independent

It was also explained to me that Virusoids are similar to Virods but they are parasitic. In other words before they can harm you the Virusoids have to attach themselves to a virus

I was looking over the web and there seems to be some dispute over what Hepitits D is caused by. Some sites are saying it is the only viroid that infects humans. Others say because it attaches itself to Hepititis B Virus the agent must be a Virusoid.

Finally a lot of sites are classing Hep D by itself and calling it a “Delta Agent.”

First correct me if I’m wrong about anything I said regarding the definitions of Viroids and Virusoids, and second what it the leading theory about what agent causes Hep D