Basically, the idea is this:
You use a variable like ?pagenum=xxx and this number points to an entry in your database that defines the objects used to build that page.
For a simple system, you could just store all the page contents on that one table, no abstraction, and all the images in /images/xxx/image01.gif or something for the page number or something similar.
Then, all the pageview.php page has to do is somthing like this:
http://server/pageview.php?pagenum=256:
<?php
/
The functions we use would be in these include files:
/
include "connect.php";
include "dbms.inc";
$page = get_results($pagenum);
print $page;
?>
Of course it can get complicated quickly if you start building a templated system, but that's basically it.