Just like the Internet, Al Gore didn’t invent it. Some of you might not be terribly nerdy/geeky/techie people, but since you are here looking at this site you are using the Internet, this should be of interest to you. If anything it will make you smarter and in a few years you can impress your friends by saying “Eh whatever, I heard about AJAX back in 2005, big deal.”
AJAX uses technology behind the scenes to communicate with a server and returns information to the page you are looking at without refreshing the page, allowing it to become truly dynamic and interactive. The best way to further explain is to see it in action and decide for yourself the cool factor.