Introduction To PHP

PHP stands for PHP: Hypertext Preprocessor. PHP is an open source scripting language. It can be embedded into HTML and so is especially suited to programming for the WWW.

The 'preprocessor' part of the name is a good hint of what it offers for a web developer. The hypertext (ie the HTML that makes up the web page) is pre-processed (ie something is done to it before it is sent to the browser). HTML, CSS and Javascript are client-side technologies. The scripts are interpreted and pages rendered by the browser, using the processing power of the client computer.

PHP is a server-side scripting language. The server is configured to use the PHP program on the server to interpret and alter files including PHP. The result of these operations is sent to the browser as HTML, CSS, Javascript, an image or any other resource that can be interpreted and displayed by a browser. PHP can also interact with other programs and files on the server in order to produce the HTML output. By connecting with a MySQL database (another open source package), it becomes possible to store information on the server.

This Guide

These pages are meant for A2 Computing students. This isn't an introduction to programming but some how to's, examples and thoughts to find your way into using PHP. You need to be confident in your understanding of HTML to make your way through this guide and would need to have some experience of programming. If you have been able to program in one language, learning another is not as hard as it sounds. You can also do a lot of cool things with PHP and make your work accessible to millions via the web. PHP is often available on cheap and free web hosting accounts.