.NET Framework Architecture

.NET framework runs on different versions of windows operating system, starting from windows 98 to latest versions of windows 7, 8, 10.

Operating system is not a part of .NET framework but generally it is shown as a base layer to indicate that .NET framework runs on operating system.

1) Common Language Runtime (CLR)

CLR is a hart of .NET Framework.
The CLR is the execution engine for .NET applications and serves as the interface between .NET applications and the operating system.
The CLR is the platform on which applications are hosted and executed.
The CLR manages memory, Thread execution, Garbage Collection (GC), Exception Handling, Common Type System (CTS), code safety verifications, and other system services.

2) Base Class Library (BCL)

It is also known as Framework Class Library (FCL)
The .NET FCL is a collection of reusable types that is integrated with the CLR.
The .NET FCL is object oriented.
It contains more than 7000 classes and data types to read and write files, access databases, process XML, display a graphical user interface, draw graphics, use Web services, etc…
The .NET FCL wraps much of the large, complex Win32 API into simpler .NET classes that can be used by C# and other .NET programming languages.

3) Data and XML Classes (ADO.NET, SQL, XML, etc…)

These classes extend the FCL to support data management and XML manipulation.
ADO.NET provides improved support for the disconnected programming model.
It also provides rich XML support.
XML classes support various operations on XML data like searching, translations, modifying, etc…

4) Applications (Windows, Web, Web Services, etc…)

Applications are the interface between users and computers that allows .NET to interact with the outside world.
Commonly used application types are windows (Tally, MS Office, etc…), web (www.asppoint.com, www.google.co.in), web services (Internet payment systems), etc…

5) Common Language Specifications (CLS)

CLS is a set of specifications to make languages as .NET compliant languages.
CLS is an agreement among language designers and class library designers to use a common subset of basic language features that all languages have to follow.
This is done in such a way, that programs written in any language (.NET compliant) can interoperate with other languages. This also can take full advantage of inheritance, polymorphism, exceptions, and other features.
CLS makes use of CTS and CLR.

6) Common Type System (CTS)

CTS describes how types are declared, used and managed in the runtime .
It facilitates cross-language integration, type safety, and high performance code execution.
Types are the mechanism by which code written in one programming language can talk to code written in a different programming language.
CTS help developers to develop applications in different languages.
The CTS also specifies the rules for type visibility and for access to the members of a type.

7) .NET Compliant Languages

This is the top most layer, it consists of .NET compliant languages e.g. C#, VB.NET, J#, VC++, F#, etc…
One of the imperative features of the .NET is the facility to program in multiple languages, which allows programmers to use their favorite languages.

About Nikunj Satasiya

I am a passionate programmer and a Software Engineer who love developing applications in Microsoft Technologies, blogging and other related technologies like Asp.Net, VB.Net, SEO, Sql Server,My SQL,Asp.Net-MVC, LINQ, C#.Net, Stored Procedures, Ajax, JavaScript, JQuery, xml etc.