I'm not a biologist, I'm a mathematician. I'm studying some viral models recently and they use variables like infected and noninfected cells, antivirals' effectiveness, etc, but also infectious and noninfectious virions.
Now I think I got what virions are (viruses in a state where they haven't entered a cell), but why is there such a thing as "noninfectious virions"? Are these just the defective copies that can't infect by themselves or what?
Also please resources to study virology otherwise I'm fucked