Microsoft has develop Dot Net with keeping in mind the world is changing and there was a need for a development which is not restricted to any platform, place and availability. So Dot Net overcome the installation, integration and legacy issues which developer faces.

It has the collection of large class library and are called as Framework Class Library (FCL). Different code written in different languages can be used it is called as language interoperability. With the use of Microsoft .Net Framework we can build Networked Applications, Distributed Web Services and Web Applications also.

Framework Class Library and Common Language Runtime both combined to make .NET Framework.

Framework Class Library (FCL) :

The Framework Class Library (FCL) is a standard library and has the collection of reusable classes, interfaces and value types. The code of FCL is BCL that is Base Class Library (BCL) which provides the most fundamental functionality. which has classes in namespaces System, System.CodeDom, System.Collections, System.Diagnostics, System.Globalization, System.IO, System.Resources and System.Text.

Common Language Runtime(CLR):

Execution of .NET programmes are managed by Common Language Runtime (CLR), which is a virtual machine component of Microsoft's .NET framework

Computer CPU executes and converts compiled code into machine language, this process is known as just-in-time compilation

Common Language Runtime other services as

a. memory management
b. type safety
c. exception handling
d. garbage collection
e. security and thread management

.NET Framework is use to develop the following types of apps and services:

• Console apps.
• Windows GUI apps (Windows Forms).
• Windows Presentation Foundation (WPF) apps.
• ASP.NET apps.
• Windows services.
• Service-oriented apps using Windows Communication Foundation (WCF).
• Workflow-enabled apps using Windows Workflow Foundation (WF).