It is necessary to have this concept in mind, so that your programming in PHP will be in lot more sense.
To proceed in our further discussion, we need to understand first what is the PHP operational trail. In this tutorial, you will be introduce about the operation of the web server to process the PHP script. But first, take a look at the diagram shown in figure 1.
Figure 1. Operational Trail
All of the process shown in figure will happen when you ask the URL in your browser before get back your HTML return back to you. As you can see, we have thereBrowser, Web Server and Apache. The diagram shows that the web browser will make a request to “find a page” and that page is located on the hard drive and in our diagram, we call it as “Test.php” and since it has a “.php” extension it tells the web browser to“process php” files and all the file that has a .php extension will be process by the web server.
If the process file contains operation on the database, then it will ask and receive data from the database. And finally, the server will then returns pure HTML code to the browser which the browser can easily understand.