Purpose of some gtk functions.

[<erikvcl silcom com>]

Hi,

I've looked through the GTK documentation for the purpose and proper use
of certain GTK functions.  The tutorial and other code shows the use of:

gtk_widget_ref
gtk_widget_unref
gtk_widget_realize

I have a general idea of what these functions do, but I was wondering if
anybody with more GTK experience than me could clarify.

Thanks,

Erik.