WordPress is what is known as a Content Management System (CMS). There are several softwares that provide this function for people to allow them to make websites. Joomla, Dot Net Nuke and Drupal are the other open source programs that provide this kind of functionality. Only WordPress makes it easy for non-programmers to create sites. The others require huge learning curves and really only shine when you know how to program in HTML5, CSS3 and PHP.