Java generics and reflection(jenkov blog)

While going through some Jakov Jenkov blogs on java reflection and generics , I found the following paragraph:

"When runtime inspecting a parameterizable type itself, like java.util.List, there is no way of knowing what type is has been parameterized to. This makes sense since the type can be parameterized to all kinds of types in the same application. But, when you inspect the method or field that declares the use of a parameterized type, you can see at runtime what type the paramerizable type was parameterized to."

Can anyone please elaborate on the paragraph?

I got confused by the statement "when runtime inspecting a parameterizable type itself"