CTS-Common Type System

In order to communicate between two language,CLR  has CTC,for example In C# it can an "Int" and in VB it "LONG",so interfacing betwwen is a difficult task,so in dot net c# it is int and in VB it is System.ToInt32 ,it is a Datatype of CTS.

CLS-Common Language Specification

It is a set rule for Compiler writer to that all Dot net Language should follow that rules.

SuniL