In the tech world you hear terms thrown around so casually, and since the tech world is a giant place, that can be a lot of terms. A lot of times you just nod your head to these terms so that you don’t look stupid amongst your peers but then realized you really don’t know what they are referring to. AJAX has been one of those things for me. I have used AJAX concepts without realizing it many times.
Further information about AJAX can be found here: https://www.keycdn.com/support/ajax-programming