The following diagram explains how the major technology components work together to deliver Australian Photography to its members.
It has been included in this thread so you will have an appreciation of what is happening and therefore be more conscious what you are doing when online.
The principals documented here apply for other technologies and Websites.
AP uses a LAMP
). Other similar software bundles/architectures exist commonly replacing Linux with another operating system (e.g. WAMP - Windows, Apache, MySQL and PHP; ) that provide similar function, although LAMP is common due to its stability, relatively low cost of deployment and the increasing ubiquity of Linux being used for servers.
Each step in the chain from clicking or typing a link in your browser and your browser then displaying a result is listed here:
- You enter a web page address in your browser's location bar (or click a link).
- Your browser breaks apart that address and sends the name of the page to the host, eg. http://www.ausphotography.net.au/forum/login.php
- The web server process on the host receives the request for login.php (part of the vBulletin PHP application).
- The web server reads the login.php file from the host's hard drive.
- The web server detects that the PHP file isn't just a plain HTML file, so it asks another process (the PHP interpreter) to process the file.
- The PHP interpreter executes the PHP code that it finds in the text it received from the web server process. Included in that code are calls to the MySQL database.
- The PHP interpreter asks the MySQL database process to execute the database calls.
- The MySQL database process returns the results of the database query.
- The PHP interpreter completes execution of the PHP code with the data from the database and returns the results to the web server process.
- The web server returns the results in the form of HTML text and images to your browser.
- Your web browser uses the returned HTML text and images to build the web page on your screen.
This may seem like a lot of steps (and at the detail level there are many more), but all of this processing happens automatically every time a web page with PHP code (i.e. vBulletin which powers AP) is requested.