In the case of creating instance, the instance of non static inner class is created with the reference of object of outer class in which it is defined. This means it have inclosing instance. But the instance of static inner class is created with the reference of Outer class, not with the reference of object of outer class. This means it have not inclosing instance.
For example:
class A
{
class B
{
// static int x; not allowed here…..
}
static class C
{
static int x; // allowed here
}
}
class Test
{
public static void main(String… str)
{
A o=new A();
A.B obj1 =o.new B();//need of inclosing instance
A.C obj2 =new A.C();
// not need of reference of object of outer class….
}
}