*-->ICloneable is  to create the copy of type instances.

*-->To create a true copy of a reference type,
you must clone the object to which it refers.

*-->The ICloneable interface identifies a type as cloneable 
and declares the Clone method as the
mechanism through which you obtain a clone of an object. 
*-->The Clone method takes no arguments
and returns a System.Object, regardless of the implementing 
type. This means that once you clone
an object, you must explicitly cast the clone to the 
correct type.


*-->If your custom type contains reference-type data 
members, you must decide whether your Clone method will 
perform a shallow copy or a deep copy.
*--> A shallow copy means that any referencetype
data members in the clone will refer to the same objects as 
the equivalent reference-type data
members in the original object.
*--> A deep copy means that you must create clones of the 
entire object graph so that the reference-type data members 
of the clone refer to physically independent copies
(clones) of the objects referenced by the original object.

Note:Mostly Shallow Copy is being Preferred.Because A 
shallow copy is easy to implement by calling the 
MemberwiseClone method from within your
Clone method.
System.Xml.XmlNode implements
a deep copy in its Clone method