1. CLS stands for Common Language Specification and it is a subset of CTS.
2. It defines a set of rules and restrictions that every language must follow which runs under .NET framework.
3. CLS enables cross-language integration.
For example:
One rule is that you cannot use multiple inheritance within .NET Framework. As you know C++ supports multiple inheritance but; when you will try to use that C++ code within C#, it is not possible because C# doesn’t support multiple inheritance.
One another rule is that you cannot have members with same name with case difference only i.e. you cannot have add() and Add() methods. This easily works in C# because it is case-sensitive but when you will try to use that C# code in VB.NET, it is not possible because VB.NET is not case-sensitive.
