1.  Private  - Client Applications cannot create the class. 
Project containing class only can create object.
2.	PublicNotCreatable- Its an internal creatable 
class. Client application can use the instance of class but 
cannot create instance on their own.
3	SingleUse – for ActiveXexe only. Every time create 
new object service will instantiate new ActiveXexe object. 
And each instance will get own copy of global variable.
4	GlobalSingleUse – Same as single use only 
difference is you can use it as a global function.
4.	MultiUse – Default. Allow any number of instance 
creatable from internally as
well as externally.
5.	GlobalMultiUse – Same as Multiuse only difference 
is explicitly instantiation of class is not required to 
access methods and properties.