Question - What is CLS (Common Language Specificaiton)?
Answer -
It provides the set of specificaiton which has to be adhered by any new language writer / Compiler writer for .NET Framework. This ensures Interoperability. For example: Within a ASP.NET application written in C#.NET language, we can refer to any DLL written in any other language supported by .NET Framework. As of now .NET Supports around 32 languages.