No worries theworks.
PR, the include('guides.php') means pull the code in from a seperate file called guides.php. That file can contain all the php and html that you need, it could even be just pure html. The same goes for the other pages that would be included. It just compartmentalises the code and makes it easier to work on. You can focus on each page seperately and not be mixing the code all in one script.
There are, as usual, several different ways to do all this, my main purpose was to illustrate the switch statement. You could for instance just send a redirection to the page itself, but then you would lose the .../index.php URL which I guess is what you are after, instead each page would have it's own normal; URL like ..../guides.php
