Common Type System

In order that two language communicate smoothly CLR has CTS (Common Type
System).
Example in VB you have “Integer” and in C++ you have “long” these datatypes are not
compatible so the interfacing between them is very complicated. In order that these two different languages communicate Microsoft introduced Common Type System. So “Integer” data type in VB6 and “int” data type in C++ will convert it to System.int32, which is data type of CTS.
CLS is subset of CTS.