A dynamic web page is a hypertext document rendered to a World Wide Web user presenting content that has been customized or actualized for each individual viewing or rendition or that continually updates information as the page is displayed to the user.

Classical web page design using only HTML or XHTML, provides static content, meaning that a page retrieved by different users at different times is always the same.

However, a web page can also provide a live user experience. Content (text, images, form fields, etc.) on a web page can change, in response to different contexts or conditions. There are two ways to create this kind of effect:

• Using client-side scripting to change interface behaviors within a specific web page, in response to mouse or keyboard actions or at specified timing events. In this case the dynamic behavior occurs within the presentation.
• Using server-side scripting to change the supplied page source between pages, adjusting the sequence or reload of the web pages or web content supplied to the browser. Server responses may be determined by such conditions as data in a posted HTML form, parameters in the URL, the type of browser being used, the passage of time, or a database or server state.

Web pages that use the first method must use presentation technology called, in a broader sense, rich interfaced pages. Client-side scripting languages like JavaScript or ActionScript, used for Dynamic HTML (DHTML) and Flash technologies respectively, are frequently used to orchestrate media types (sound, animations, changing text, etc.) of the presentation. The scripting also allows use of remote scripting, a technique by which the DHTML page requests additional information from a server, using a hidden Frame, XMLHttpRequests, or a Web service.

Web pages that use to the second method are often created with the help of server-side languages such as PHP, Perl, ASP, ASP.NET, JSP, ColdFusion and other languages. These server-side languages typically use the Common Gateway Interface (CGI) to produce dynamic web pages. These kinds of pages can also use, on the client-side, the first kind (DHTML, etc.).