Static websites are websites that serve the same content to every visitor from a fixed file coded in HTML. They are less complex, faster and less expensive. Dynamic websites are interactive and capable of serving different content to web visitors, even when they are viewing the same URL. They are written in a server-side scripting language such as PHP, ASP etc. An example of this is when customers log on to Ecommerce websites and view prices in different currencies based on their IP address. Most static sites use a CMS {Content Management System} that allows internal users to make updates and changes.
Choosing to build a static or dynamic website depends on the size of the website, the team managing it, frequency of updates, and budget.