MSIL are simple binary structures that are similar to the instruction sets of the CPU. Like the instruction set, it encodes a wide spectrum of operations such as loading, storing, arithmetic and logical operations and control flow. The similarity to the machine code enables the code to be compiled quickly in the Just in time compiler. The type verification also becomes simpler because the DotNet binary contains tables of metadata. The metadata defines each type and its signatures and also the other data that the runtime locates and extracts from the file at the time of execution. The presence of the metadata makes the module self descriptive and eliminates the need for IDL files and header files. However, unlike the CPU instruction set, MSIL expresses object oriented concepts such as object creation, method invocation, property access and exception handling.
It is the Microsoft Intermediate Language (MSIL) which makes applications language independent. Applications may be created by programmers in any language of their choice—ASP.NET or VB.NET—in a machine on which the .NET framework has been installed. The compiler then, gives an output in the Microsoft Intermediate language. This language can be defined as a kind of assembly language at a higher level of abstraction. The language is designed in a manner that makes it possible to convert it into any kind of native machine code with ease. The CLR detects the Intermediate language and invokes the Just-in-time compiler to convert the language into machine code.