What are dynamic web pages?
I just thought that the more information I get the difference a static site is vs. a dynamic site, the better one will understand what goes on behind the curtains. Below I have copied and pasted someone else's description on the topic.
To understand dynamic web pages you have to understand normal web pages. Typical non-dynamic web pages do not change every time the page is loaded into the browser, nor do they change if a user clicks on a button. The only change that you will see in static pages is to see them load and unload, like what happens when you click on a hyper link.
In a nutshell: static web pages (normal pages you build) always look the same and the content never changes unless you load a new page or you change the page yourself and upload the new version of the pages unto the server.
Dynamic pages do the opposite, they can change every time they are loaded (without you having to make those changes) and they can change their content based on what user does, like clicking on some text or an image. (I am not talking about loading a new page!)
One of the most common types of dynamic web pages is the database driven type. This means that you have a web page that grabs information from a database (the web page is connected to the database by programming) and inserts that information into the web page each time it is loaded. If the information stored in the database changes, the web page connected to the database will also change accordingly and automatically without human intervention.
This is commonly seen on online banking sites where you can log in (by entering your user name and password) and check out your bank account balance. Your bank account information is stored in a database and has been connected to the web page with programming thus enabling you to see your banking information. Imagine if the web page holding your banking information had to be built traditionally (that is by hand.) every time your bank balance changed! Even a thousand monkeys working 24/7 drinking 5 cups of coffee a day, would not be able to keep up!
Hopefully you are starting to see why you would want a database driven site; you would want it if your information changes very often, just like in a banking site.
Database driven sites can be built using several competing technologies, each with it's own advantages. Some of those technologies/tools include: PHP, JSP, ASP, PERL, Cold Fusion.