A "flat or Static" website is one built out of static HTML pages. A dynamic Website is any Website which has content that is changed by a program or script at the time the page is requested. Static Websites contain files that can only be changed manually, and then added to the Website.

Dynamic Websites are made up of templates (look and feel) and Web content. In a dynamic website the content is accessed from a database (like Access, SQL Server, or MySQL) rather than an HTML file living on the server. Any company that wants the Web to work for them (so they can better interact with their users or customers) needs a dynamic website.