WordPress is a free and open-source content management system (CMS) based on PHP and MySQL. WordPress is installed on a web server, which either is part of an Internet hosting service or is a network host itself; the first case may be on a service like WordPress.com, for example, and the second case is a computer running the software package WordPress.org. An example of the second case is a local computer configured to act as its own web server hosting WordPress for single-user testing or learning purposes. Features include a plugin architecture and a template system. WordPress was used by more than 26.4% of the top 10 million websites as of April 2016. WordPress is reportedly the easiest and most popular website management or blogging system in use on the Web, supporting more than 60 million websites.