Boxing
Converting value-type to object(System.Object). For example,
    int a = 10;
    object  obj = a;
Unboxing
Converting object(System.Object) to value-type. For example,
    int b = (int) obj;
Converting value-type to object(System.Object). For example,
    int a = 10;
    object  obj = a;
Converting object(System.Object) to value-type. For example,
    int b = (int) obj;