A programming infrastructure created by Microsoft for building, deploying, and running applications and services that use .NET technologies, such as desktop applications and Web services.
The .NET Framework contains three major parts:
CLR
Short for Common Language Runtime, a runtime environment that manages the execution of .NET program code and provides services such as memory and exception management, debugging and profiling, and security. The CLR is a major component of the .NET framework.
CLR also is known as the Virtual Execution System (VES).
FCL
Short for framework class library, the collective name for the thousands of classes that compose the .NET Framework. The services provided by the FCL include runtime core functionality (basic types and collections, file and network I/O, accessing system services, etc.), interaction with databases, consuming and producing XML, and support for building Web-based and desktop-based client applications, and SOAP-based XML Web services.
ASP.NET
A Microsoft server-side Web technology. ASP.NET takes an object-oriented programming approach to Web page execution. Every element in an ASP.NET page is treated as an object and run on the server. An ASP.NET page gets compiled into an intermediate language by a .NET Common Language Runtime-compliant compiler. Then a JIT compiler turns the intermediate code to native machine code, and that machine code is eventually run on the processor. Because the code is run straight from the processor, pages load much faster than classic ASP pages, where embedded VBScript or JScript had to be continuously interpreted and cached.
ASP.NET is used to create Web pages and Web services and is an integral part of Microsoft's .NET vision.
