One of the main advantages of object-oriented programming is code reuse; classes can be shared among programs. By using already-written classes you can save yourself a lot of work. An organizational unit containing shared code components is known as a namespace. One of the most exciting things about Visual Basic .NET is the amount of functionality available from classes built into the .NET framework. Table 5.1 lists a few examples of some namespaces provided by the .NET framework for use in your programs.
|System.Drawing.Graphics||Drawing lines, and so on|
|System.Diagnostics||Diagnostics, error log|