WordPress, also known as WP or WordPress.org, is a content management system (CMS) that is both free and open-source. It is primarily written in PHP and is used in conjunction with a MySQL or MariaDB database that supports HTTPS. Some of its key features include a plugin architecture and a template system, which are referred to as “Themes” within the WordPress platform.

Initially designed as a blog-publishing system, WordPress has since expanded to support a variety of web content types, including mailing lists, media galleries, online forums, membership sites, learning management systems (LMS), and online stores. As of October 2021, WordPress is used by 42.8% of the top 10 million websites.