The .NET Framework provides a huge class library—something on the order of 6,000 types. To help developers navigate though the huge hierarchy of types, Microsoft has divided them into namespaces. However, even the number of namespaces can be daunting. Here are the most common namespaces and an overview of what they contain:
Runtime support for applications written in Visual Basic .NET. This namespace contains the functions and procedures included in the Visual Basic .NET language.
Types that access the Windows Registry and provide access to system events (such as low memory, changed display settings, and user logout).
Core system types, including:
Implementations for Visual Basic .NET’s fundamental types (see “Types” in Chapter 2 for a list of fundamental types and the .NET classes that implement them).
Common custom attributes used throughout the .NET Framework class library (see Appendix A), as well as the Attribute class, which is the base class for most (although not all) custom attributes in .NET applications.
Common exceptions used throughout the .NET Framework class library (see Appendix B), as well as the Exception class, which is the base class for all exceptions in .NET applications.
The Array class, which is the base class from which all Visual Basic .NET arrays implicitly inherit.
The Convert class, which contains methods for converting values between various types.
The Enum class, ...