PHP is a server-side scripting language that can underpin a wide range of web applications, providing the backbone for their backend development. From popular Content Management Systems like WordPress to social networking applications, eCommerce platforms, and enterprise-level applications such as ERP and CRM software, PHP can be used to develop them all. Commercial platforms like Wikipedia, Vimeo, Etsy, Mailchimp, Yahoo, Flickr, and Magento are just a few examples of the breadth of applications written in PHP.