CLS:Comman Language Specification. it is Subset of CTS. CTS:Comman Type systemes. it can have different Types of Datatypes. it can be supports two types. 1)Value Type. 2)Refference type. 1)Value type: It can Allocated Memory in Stack, Ex:int i =10; I value goes to stored in stack memory,int,float,struct etc. 2)Refference type:It can Allocated Memory in Heap . ex:class,object, delegate,interface,string etc.