[.net] What does "Object reference not set to an instance of an object" mean?

If I have the class:

public class MyClass
{
   public void MyMethod()
   {

   }
}

and I then do:

MyClass myClass = null;
myClass.MyMethod();

The second line throws this exception becuase I'm calling a method on a reference type object that is null (I.e. has not been instantiated by calling myClass = new MyClass())