While i agree it shouldn't be restricted there are better places to discuss this matter
I wish not to engage in such discussion and focus on the true purpose of this platform.
I will also ask you kindly to remove content irrelevant to coding from this thread and wish you a good day.
raza naqvi other than w3schools IBM also has a good tutorial
Regarding AJAX, they are just few JS methods to fetch /send resources from a server. Xml is not used much but JSON is more prevalent these days.
Here's a simple demo of AJAX