Introduction

The code which is executing with the help of CLR is called as managed code. The code which is targeting operating system while execution is called as unmanaged code or Code that runs outside the CLR is referred to as "unmanaged code." COM components, ActiveX components, and Win32 API functions are examples of unmanaged code. Unmanaged code uses registry of operating system. Managed code is faster in execution

About CLR: CLR is common language runtime. It is a standard runtime execution engine for managed code.
While executing the Dot Net application, in the client machine only Dot Net framework software is enough.
Dot Net framework will be installed by default with Dot Net software, if required CLR can be installed separately also.
CLR related files will be stored in C:\windows\system32 folder. In CLR software the most important file name is mscoree.dll.
.dll file is not self executable, it depends on another, it can be reusable, .exe is self executable.

Current Versions Of Dot Net:

1. Dot Net frame work version - 4.0
2. Dot Net IDE version - 2010
3. VC#.Net language version - 4.0
4. CLR version - 4.0.31106.0

Language Interoperability: It is a concept of developing an application with the help of more than one DotNet programming language. Whenever a program is compiled that will be converted into byte code or MSIL(Microsoft intermediate language code). This byte code follows a standard instruction set which is specified by CLS(Common language specification). CLS specifies the common syntaxes for all the DotNet programming languages.

AppDomain (Application Domain): An application domain can be considered similar to a lightweight OS process, and is managed by the common language runtime.