The #GtkTreeSelection object is a helper object to manage the selection for a #GtkTreeView widget. The #GtkTreeSelection object is automatically created when a new #GtkTreeView widget is created, and cannot exist independently of this widget. The primary reason the #GtkTreeSelection objects exists is for cleanliness of code and API. That is, there is no conceptual reason all these functions could not be methods on the #GtkTreeView widget instead of a separate function.