PHP is a server-side scripting language that enables you to build dynamic web pages. PHP pages may contain text, HTML, and script blocks. When a browser requests a PHP page, the PHP script is executed on the web server, and the resulting HTML is displayed in the browser.
A PHP page must have a PHP-supported extension. Typically, a PHP file ends with .php, although other PHP extensions such as .php4 and .phtml also exist. However, .php is the most common extension.
WHY LEARN PHP?
PHP is one of the simplest server-side languages out there, and it was designed primarily for web development. Learning PHP is good not only because it adds one more language to your toolbelt, but also because there is a large number of sites currently built with Wordpress, a content management system (CMS) built with PHP.
By end the end of this course, you'll have gained familiarity with a very convenient, flexible server-side language: PHP. You'll be exposed to many fundamental programming concepts such as data types, functions, control flow, and more.
Overview of the MySQL PHP drivers
Depending on the version of PHP, there are either two or three PHP APIs for accessing the MySQL database. PHP 5 users can choose between the deprecated mysql extension, mysqli, or PDO_MySQL. PHP 7 removes the mysql extension, leaving only the latter two options.