❔ Why is typeof(T).FullName a ``string?``, but typeof(T).Name a ``string``

And in which instances is

typeof(T).FullName

typeof(T).FullName

potentially

null

null

? Is there a circumstance in which I can't rely on that field being available?

❔ Why is typeof(T).FullName a ``string?``, but typeof(T).Name a ``string`` - C#