What represents reflection TypeVariable interface

I'm trying to read and understand the different interfaces and classes used by java reflection mechanism, but I didn't understand what really represent the instances of classes implementing the TypeVariable interface ?

And also the following quotation from official documentation is really ambiguous :

If a type variable t is referenced by a type (i.e, class, interface or annotation type) T, and T is declared by the nth enclosing class of T (see JLS 8.1.2), then the creation of t requires the resolution (see JVMS 5) of the ith enclosing class of T, for i = 0 to n, inclusive. Creating a type variable must not cause the creation of its bounds.

Can anyone give me a small example explaining clearly what the meaning of the above paragraph?

Thanks in advance.