What's a boxed type? (was Re: binding how-to)

[Joe Smith <jes martnet com>]

muppet wrote:
> ... i walk you through binding a fictional C library to perl ...

Cool; great resource.

This sent me back to re-read the 'new-gtk2-perl' doc as well.  Now, I 
finally give up and admit that I don't understand what a 'boxed' type 
is.  I mean, how is a boxed type different from the other {G,Gtk}Object 
wrappers?

Clues greatfully accepted ...

<Joe