what is the difference between boxing and unboxing in c#.net?

Question

And which is used when?

Answer 1

Boxing : Converting value type to object
Example :
int a=50;
object o=a;

UnBoxing: Converting object type to Value type
Example

object o=21;
int a=(int)o;

Comments

converting a value type into a reference type is called boxing then, that reference type again converted to a value type is called un-boxing...
Boxing: int i=100;
obj obj=i;

Un-Boxing: int j= Convert.ToInt32(obj);