Part I:The .NET Framework
.NET is a collection of tools, technologies, and languages that all work together in a
framework to provide the solutions that are needed to easily build and d eploy truly robust
enterprise applications. These .NET applications are also able to easily communicate with one
another and provide information and application logic, regardless of pla tforms and languages.
Sounds pretty outstanding, doesn t it?
Figure 1-1 shows an overview of the structure of the .NET Framework.
Figure 1-1: The .NET Framework.
The first thing that you should notice when looking at this diagram is t hat the .NET
Framework sits on top of the operating system. Presently, the operating systems that can take
the .NET Framework include Windows XP, Windows 2000, and Windows NT. The re has also
been a lot of talk about .NET being ported over by some third-party comp anies so that a
majority of the .NET Framework could run on other platforms as well.
NOTE: The support for the .NET Framework on Windows NT is limited to functioning only as a client.
NT will not support the Framework as a server.
At the base of the .NET Framework is the Common Language Runtime (CLR) . The CLR is
the engine that manages the execution of the code.
The next layer up is the .NET Framework Base Classes. This layer contains classes, value
types, and interfaces that you will use often in your development proces s. Most notably within
the .NET Framework Base Classes is ADO.NET, which provides access to and management
The third layer of the framework is ASP.NET and Windows Forms. ASP.NET should not be
viewed as the next version of Active Server Pages after ASP 3.0, but as a dramatically new
shift in Web application development. Using ASP.NET, it s now possibl e to build robust Web
applications that are even more functional than Win32 applications of th e past. This was
always quite difficult to do in the stateless nature of the Internet, bu t ASP.NET offers a
number of different solutions to overcome the traditional limitations on the types of
applications that were possible. The ASP.NET section of the .NET Framewo rk is also where
the XML Web services model resides.