Runtime Types in Reflection
Reflection provides classes, such as Type and MethodInfo, to represent types, members, parameters, and other code entities. However, when you use reflection you don't work directly with these classes, most of which are abstract (MustInherit in Visual Basic). Instead, you work with types provided by the common language runtime (CLR).
For example, when you use the C# typeof operator (GetType in Visual Basic) to obtain a Type object, the object is really a RuntimeType. RuntimeType derives from Type, and provides implementations of all the abstract methods.
These runtime classes are internal (Friend in Visual Basic). They are not documented separately from their base classes, because their behavior is described by the base class documentation.