Q:

What does "dynamic" actually mean?

I keep hearing, especially here on StackOverflow, about people generating webpage content "dynamically."  Does this mean generating content anytime after design time, or only on the client side, or some other definition?  
In other words, as it relates to web development, what is the definition of "dynamic"?

A:

This means that you are generating HTML through code, i.e., PHP, python, etc.  Instead of hosting static HTML pages, you can generate HTML which is representative of the current state of your site/DB.

A:

As with any popular word, people use it to mean many different things.

Original definition: static web pages were just a file that the server read off the disk and served verbatim. dynamic pages included code, such as PHP, that was interpreted by the server and replaced with specially-tailored information before it was sent to the user.

Static pages don't really exist anymore. Any site you care about will be "dynamic" in some form. As a result, the term got recycled to mean any number of things:

A page that rearranges its DOM and/or CSS after it has been received from the server. This is usually accomplished with Javascript, and may involve hiding/showing different parts of the page or displaying them in different ways. For example, a tabbed interface that displays different pieces of the page depending on which tab the user clicks on.
A page that requests new information from the server with AJAX requests and displays it using a method similar to #1. For example, user clicks on "More..." next to an article stub and the entire article is loaded and displayed without the need for a full page refresh.

