Wasn't it Fred Brooks that wrote in the Mythical Man month: give me
your
data structures, and I won't need your algorithms; give me your algorithms, and they will mean nothing without your data structures?
Brooks was good for his time, but Steve McConnell's "Rapid Development" is my software bible. You can find excerpts at www.construx.com
The interaction as I see it is a PHP module in the Apache web server runs some custom PHP code that connects to a MySQL database, runs queries, and uses the results to construct the appropriate pages.
This is the part I know. I need more detail.
Ed Poor