What does this mean and what difference does it make?

Traditional static websites are what you find many companies still using today.  All of the content is hard coded in a HTML text file.  While this age old method is extremely effective, it has one flaw.  Because all of the content is hard coded, a webmaster has to update the content on every page by hand.  With the internet becoming even more of a super highway for everyday communication, it is simply impossible for a webmaster to update the content fast enough.  This is where the benefits of dynamic coding come into play.  Dynamic coding automatically updates, which eliminates nearly all of the hassle of updating a traditionally coded website.  Ultimately, this saves you the customer a lot of money.

What do I need to make the switch?

Joomla and Wordpress are currently two of the most popular dynamic web applications, and they are both absolutly FREE.  One particular benefit of these two pieces of software is that they are 100% web based.  This means that you and anybody else with a proper account can update the website from ANY web enabled device without any coding knowledge whatsoever.  It is truly as simple as using a word proccesor.