Asynchronous Put the “A” in AJAX
The key word is asynchronous.
“1.  A process in a multitasking system whose execution can proceed independently, “in the background”. Other processes may be started before the asynchronous process has finished.”—Dictionary.com
Most web pages are rather “choppy” because they need to “refresh” themselves, which is a nice way of saying completely re-load the entire page. This must happen every single time they need to “refresh” their data from the server. You probably have figured out by now that this takes time. What AJAX does is allow a web page to asynchronously update only the portion of the web page that is actually in need of fresh data instead of the entire page. Not only is it much faster, but the effect is that it is much smoother. This is because your eye does not have to endure the “flicker” or “hang ups” of the complete page re-load. Sometime the transaction is so smooth that the user often has no idea that it has happened. Knowing that you have affect