What is Common Language Runtime

Before reading about what is CLR it is necessary to know about the IL(Intermediate Language).
Read our previous article about IL(Intermediate Language)

Full form of CLR is Common Language Runtime and it forms the heart of the .NET framework.
All Languages have runtime and its the responsibility of the runtime to take care of the code
execution of the program. For example VC++ has MSCRT40.DLL,VB6 has MSVBVM60.DLL,
Java has Java Virtual Machine etc. Similarly .NET has CLR.



Following are the responsibilities of CLR

Garbage Collection :- CLR automatically manages memory thus eliminating memory leaks. When objects are not referred GC automatically releases those memories thus providing efficient memory management.
Code Access Security :- CAS grants rights to program depending on the security configuration of the machine. Example the program has rights to edit or create a new file but the security configuration of machine does not allow the program to delete a file. CAS will take care that the code runs under the environment of machines security configuration.
Code Verification :- This ensures proper code execution and type safety while the code runs. It prevents the source code to perform illegal operation such asaccessing invalid memory locations etc.
IL( Intermediate language)-to-native translators and optimizer’s :- CLR uses JIT and compiles the IL code to machine code and then executes. CLR also determines depending on platform what is optimized way of running the IL code.

The CLR allows programmers to ignore many details of the specific CPU that will execute the program. It also provides other important services, including the following:

1. Memory management
2. Thread management
3. Exception handling
4. Garbage collection
5. Security

For more detail about Common Language Runtime Overview please visit MSDN.