Intermediate Language (IL)

Also referred to CIL (Common IL) or MSIL (Microsoft IL).

I think ILAsm (IL Assembly Language) is also the same thing but not really sure. (not ILASM, the assembler)

Common Language Infrastructure (CLI)

It is an open specification developed by Microsoft and standardized by ISO and Ecma.

Examples: .NET Framework, .NET Core, Mono

Among other things, CLI describes the following 4 aspects:

  • CTS or Common Type System

  • Metadata: Info about language structure

  • CLS or Common Language Specification: For inter-operability between languages

  • VES or Virtual Execution Engine: For compiling IL to native code and running it.