Example of a Client - Server relationship:

  1. The browser (client) requests a page from the web server.
  2. Apache looks for the file and hands off the processing of the contents to PHP.
  3. The PHP application processes the scripting on the page. If there are queries on the page, PHP retrieves information from the database application. PHP passes the content and HTML markup to Apache.
  4. Apache returns the document to the browser.

Note: PHP requires Apache or another web server application to run.