Self is an implicit variable which can only be used within class methods, and refers to the current class instance. So "Self" within a method of the TForm class refers to the current instance of TForm . When you create a form or component, you pass its owner in the constructor. When a form or component is freed, it automatically frees all the components which it owns as well. So if you pass an Application as the owner when you create a form instance, the form instance will be automatically freed when the Application is freed. If you pass a form instance as the owner when you create another form instance, the second form will be freed when the first is freed.