Main Feartures Of .NET Framework
1.Common Language Runtime(CLR) :-Full form of CLR is Common Language Runtime and it forms the heart of the .NET framework.
All Languages have runtime and it is 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,
and 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 as accessing
invalid memory locations etc.
• IL (Intermediate language)-to-native translators and optimizer’s:- CLR uses
JIT, 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.
2. CTS (Common Type System):-
In order that two language communicate smoothly CLR has CTS (Common Type
System).Example in VB you have “Integer” and in C++ you have “long” these datatypes are not
compatible so the interfacing between them is very complicated. In order that these two different
languages communicate Microsoft introduced Common Type System. So “Integer” data type in
VB6 and “int” data type in C++ will convert it to System.int32, which is data type of CTS. CLS,
which is covered in the coming question, is subset of CTS.
3. CLS (Common Language Specification):-
This is a subset of the CTS, which all .NET languages are expected to support. It was always a
dream of Microsoft to unite all different languages in to one umbrella and CLS is one-step
towards that. Microsoft has defined CLS, which are nothing but guidelines, that language should
follow so that it can communicate with other .NET languages in a seamless manner.
4. Managed Code
Managed code runs inside the environment of CLR i.e. .NET runtime. In short, all IL are
managed code. However, if you are using some third party software example VB6 or VC++
component they are unmanaged code, as .NET runtime (CLR) does not have control over the
source code execution of these languages.
5. CODE Access security :-
CAS is part of .NET security model that determines whether a piece of code is allowed to run and
what resources it can use while running. Example CAS will allow an application to read but not
to write and delete a file or a resource from a folder.