What should i use? Override or reload?

Question

I am just working on a book on OOP (Object Oriented Programming with Visual Basic.NET from JPHamilton). The moment he explained the overload, but not yet redefining it, he writes: “You can overload methods only in the class, which means that you can add new methods with the same name as existing methods. However, existing behavior cannot be overridden. "

But as I understand it, you can override a method from a child class using overload, for example:

Public Class clsTest
    Sub addition(ByVal x As Integer)
        MsgBox(x)
    End Sub
End Class

Public Class clsTest2 : Inherits clsTest
    Overloads Sub addition(ByVal x As Integer)
        MsgBox(x * x)
    End Sub
End Class

If this is correct, then I would like to know when to use overloading and when to use override to override the method, since

Public Class clsTest
    Overridable Sub addition(ByVal x As Integer)
        MsgBox(x)
    End Sub
End Class

Public Class clsTest2 : Inherits clsTest
    Overrides Sub addition(ByVal x As Integer)
        MsgBox(x * x)
    End Sub
End Class

gives me the same result.

Answer 1

: "?" VB.NET. , , . Shadows, Overloads , . , Overloads , .

, - , . , . , , , . :

  Dim obj As ClsTest
  obj = new ClsTest2
  obj.addition(42)     '' Calls ClsTest.addition

, ClsTest2.addition(), ClsTest2. , , . ClsTest2.addition(), . , , .