What is .NET Framework?

• .Net Framework is a software Framework developed by Microsoft that runs primarily on Microsoft windows.

• It Includes large libraries and provides language Interoperability across several programming Language.

• Programs Written in .Net Framework executes in software environment known as Common Language Run time (CLR).

• The Class Library and CLR together constitutes the .NET Framework.

• .NET Framework's Base Class Library provides user interface, data access, database connectivity, cryptography, web application development, numeric algorithms, and network communications. Programmers produce software by combining their own source code with .NET Framework and other libraries.

   Design Features: 

•  Interoperability
•  Portability.
•  Security
•  Common Language Run time(CLR)
•  Language Independence.
•  Base Class Libraries.

 

  Architecture of .Net Framework

  

          Common Language Infrastructure (CLI):  

• The main purpose if Common Language Infrastructure is to provide a language neutral platform for application development and execution, including function for exception handling, garbage collection, security and interoperability.

•  By implementing the core aspects of .NET Framework within the scope of the    CLI, this functionality will not be tied to a single language but will be available  across the many languages supported by the framework. Microsoft's  implementation of the CLI is called the Common Language Run time, or CLR. 

             Diagrammatic Overview of the Common Language Infrastructure

               

         What is Common Intermediate Language ?         

     

• During compilation of CLI programming languages, the source code is                   translated into CIL code rather than platform or processor-specific object code.
• CIL is a CPU- and platform-independent instruction set that can be executed in any environment supporting the Common Language Infrastructure,such as the.NET run-time on Windows, or the cross-platform Mono runtime. 
• In theory, this eliminates the need to distribute different executable files for different platforms and CPU types. 
• CIL code is verified for safety during runtime, providing better security and reliability than natively compiled executable files.

     The execution process looks like this:

• Source code is converted to Common Intermediate Language (CIL), which is the CLI's equivalent to Assembly language for a CPU.
• CIL is then assembled into a form of so-called bytecode and a CLI assembly is created.
• Upon execution of a CLI assembly, its code is passed through the run time's JIT compiler to generate native code. Ahead-of-time compilation may also be used, which eliminates this step, but at the cost of executable file portability.
• The native code is executed by the computer's processor.