Common Type System

Common Type System (CTS) describes a set of types that can be used in different .Net languages in common . That is , the Common Type System (CTS) ensure that objects written in different .Net languages can interact with each other. For Communicating between programs written in any .NET complaint language, the types have to be compatible on the basic level .

These types can be Value Types or Reference Types . The Value Types are passed by values and stored in the stack. The Reference Types are passed by references and stored in the heap. Common Type System (CTS) provides base set of Data Types which is responsible for cross language integration. The Common Language Runtime (CLR) can load and execute the source code written in any .Net language, only if the type is described in the Common Type System (CTS) .Most of the members defined by types in the .NET Framework Class Library (FCL) are Common Language Specification (CLS) compliant Types.

Suppose that one of the methods is defined in VB.net class that returns an Integer, and if we call this method in C# defined class by implementing the inheritance but C# does not have any data type of that name. So this problem is circumventing by CTS. In VB.net Integer is actually a 32-bit signed integer that maps exactly to the IL type code, known as Int32. At source level, C# refers to Int32 with the keyword int. so the compiler will simply treat the VB.net methods as if it returned an int.