WordPress is a free and open source blogging product based on PHP and MySQL and a content management system (CMS), which runs on a web hosting service. It is one of the most popular blogging systems due to his rich feature set and enhancements. It comes in two flavours. WordPressorg is an open source CMS that is created, supported, managed, and maintained by the community of passionate developers. WordPresscom is a shared hosting platform that manages security, updates, and backups for its users. As a user you need not to worry about installation and other stuffs in wordpresscom.