# Introduction PHP

# About PHP

PHP is a popular server-side scripting language especially suited to web development
- PHP scripts are executed on a web server, in contrast to client-side scripting languages as JavaScript, jQuery, ...
PHP runs on multiple platforms (Linux, Windows, macOS) and is supported by most web server technologies (Apache, Nginx, IIS)
PHP is free to use and to host
A lot of software is written in PHP like Joomla, Drupal, Magento, ...
There are lots of available PHP frameworks like Symfony, Laravel, Zend, CodeIgniter, ...
PHP was originally created by Rasmus Lerdorf in 1994 and stood for "Personal Home Page". Nowadays it's a (recursive) acronym for "PHP: Hypertext Preprocessor".
PHP syntax has a lot of similarities with the C style (C, C#, Java, JavaScript, ...) syntax
We use the 8.1.x version in this course; see Config > Work environment

How does PHP work?

A client calls a PHP page (containing HTML and PHP scripts) in his browser: https://pverhaert.sinners.be/hello_world.php (opens new window)
The client's browser contacts the web server
The web server executes the PHP scripts in hello_world.php (and communicates with the database if necessary), and translates them to HTML code
The result (plain HTML) is sent to the client's browser

During development, it's easier to work with a local webserver (in order to avoid uploading files after every change)
Most popular are the so-called XAMP implementations (for example Ampps (opens new window)), where
- X stands for W(indows) -> WAMP, L(inux) -> LAMP or M(acOS) -> MAMP
- A stands for Apache
- M stands for MySQL
- P stands for PHP
In this course, we will use Homestead, which is a virtual web server environment (including Nginx, MySQL, PHP, ...) that runs on Windows, Linux and MacOS
- Part of Laravel, but can be used for classic PHP web applications as well