Common Language Specification known as CLS in .Net Framework, CLS is one of the core components in .net framework.
CLS stands for Common Language Specification. CLS defines rules and restrictions that any .Net language must follow, CLS helps in interoperability and in cross-language integration.
CLS defines the necessary standard for any .Net language, so that any language can interoperate with other language.
For example in C# language any statement will end with semicolon, this has been specified in CLS, if we don't put the semicolon then compiler will throw an error.
CLS (Common Language Specification) is the subset of CTS