[Dynamic title tags header.php]

Hello group,

 

Apologies if this has been asked. I have a site that is generating pages like this:

http://www.example.com/index.php?title_page=products_info&cPath=143&products_id=001

http://www.example.com/index.php?title_page=RFEE_SaaS_Cloud_Services

http://www.example.com/index.php?title_page=customer_inquiry&src=mnu

 

I want to create dynamic meta data in the header.php

ex:

<title><?php echo $pageTitle; ?></title>

<meta name="description" content="<?php echo $pageDescription; ?>">

 

I'm new to the more advanced functions of php so my question is... where are the values for $pageTitle and $pageDescription stored if every page seems to reference index.php as the page (although there might be dynamic functionality within this page I suppose)? I could understand if the pages referenced were all different like products.php, services.php, etc. I'm looking at the URLs generated on the site and am trying to figure this out.

 

Thanks.