First off let me state that I know html and javascrip/jquery are clientside and php& mysql are server side languages.

As I learn more and more about these languages I a want to start using object oriented php but I first need to understand how all of the files go to together with the languages. Currently in my 'learning' erb app jquery is calling individual php files (via url) and echoing the results to calback functions and results are displayed to the user, works great and I am happy with the results. There are lots of individual php files doing there job like getting a json array of categories, status' project contacts etc . .. . .. but.

Where in this picture does oo php come in...... you know 'one' php file that has a class for lets say "projects" that has all of the methods necessary calculate and return everything 'project related'. Jquery itself cannot run an individual method inside of a php class file. Do I still have to have all of the individual php files for jquery to pass the url too which then in turn communicate the the class methods...

I apologize if this is a stupid question but I would like to get it right from the the start and I have no local mentors to bounce this off......

Thanks in advance