GTK Signals documentation

[Worik <worik noggon com>]

Friends

I am  in desperation as I can find no place that describes what gtk 
signals *mean*.


Eg: From the dev-book documentation

>
> The "cursor-changed" signal
>
> void        user_function                  (GtkTreeView *treeview,
>                                             gpointer user_data);
>
> treeview :    the object which received the signal.
> user_data :    user data set when the signal handler was connected.



But *when* is this signal emitted and *why*?  And not just this signals, 
but all signals.

I have no confidence I am using the correct signal handlers.

In friendly frustration
Worik