Common Language Specification (CLS) : Common Language Specification (CLS), which is a set of basic language features needed by many applications, has been defined. It's a subset of the common type system. Targeting the CLS is an excellent way to ensure cross-language interoperation.
Common Type System (CTS) : The CLR is based on a type system and a programming model that are collectively known as the Common Type System (CTS). The common type system establishes a framework that enables cross-language integration, type safety, and high-performance code execution. Ex VB.NET Integer and a C# int are both represented in IL code as System.Int32
