Anatomy of a WordPress Site
A WorPress site is comprised of three main components:
The WordPress application – a PHP-based Content Management software that is installed on the server.
A database that stores all the content of the site, including text, images and other media.
A theme – a set of php files that specify the design of the site. Because the theme (the design) is separated from the database (the content) it can be changed easily without affecting the site’s content.