What is IL?

MSIL stands for Microsoft Intermediate Language. We can call it as Intermediate Language (IL) or Common Intermediate Language (CIL).

A.NET programming language (C#, VB.NET, J# etc.) does not compile into executable code; instead it compiles into an intermediate code called Microsoft Intermediate Language (MSIL).

MSIL:

During the compile time, the compiler convert the source code into Microsoft Intermediate Language (MSIL) .MSIL is a CPU-independent set of instructions that can be efficiently converted to the native code.

MSIL TO JIT:

During the runtime the CLR Just In Time (JIT) compiler converts the Microsoft Intermediate Language (MSIL) code into native code to the Operating System. When a compiler produces Microsoft Intermediate Language (MSIL), it also produces Metadata. The Microsoft Intermediate Language (MSIL) and Metadata are contained in a portable executable (PE) file .

Microsoft Intermediate Language (MSIL) includes instructions for loading, storing, initializing, and calling methods on objects, as well as instructions for arithmetic and logical operations, control flow, direct memory access, exception handling, and other operations Just In Time Compiler

Processor execution:

The computer's processor executes the native code.