A web page can be static or dynamic. Static pages, such as a regular HTML page that you might create with Dreamweaver, are those which have been created once and do not have to be regenerated every time a person visits the page. In contrast, dynamic pages, such as those you create with WordPress, do need to be regenerated every time they are viewed; code for what to generate on the page has been specified by the author, but not the actual page itself. These use extensive PHP code which is evaluated each time the page is visited, and the content is thus generated upon each new visit.
Almost everything in WordPress is generated dynamically, including Pages. Everything published in WordPress (Posts, Pages, Comments, Blogrolls, Categories, etc…) is stored in the MySQL database.
An example of a static page might be an HTML document (without any PHP code). The problem with purely static pages is that they are difficult to maintain. Changes you make to your WordPress settings, Themes and Templates will not be propagated to pages coded only in HTML. The Page feature of WordPress was developed to alleviate this problem. By using Pages, you no longer have to update your static pages every time you change the style of your site. If written properly, your dynamic Pages will update along with the rest of your blog.
Despite the dynamic nature of Pages, many people refer to them as being static. They are actually called “pseudo-static” web pages. In other words, a Page contains static information but is generated dynamically. Thus, either “static,” “dynamic,” or “pseudo-static” may be validly used to describe the nature of the WordPress Page feature.