AJAX

AJAX is the acronym for Asynchronous JavaScript and Xml
This is a general term used to describe the technique used on the client side to create asynchronous web applications that communicate with a server.
This general term refers to using [[XMLHttpRequest]] to retrieve data in any format from a server. It's not just limited to XML.
The JQuery library contains code for calling XMLHttpRequest.

$.getJSON(url, '---').done(function (result) {  
}) 
.done( function (result) { 
}) 
.fail( function (error) { 
   app.showNotification("cannot fetch data", error.statusText); 
} 

$.ajax({ 
  url: "test.html", 
  context: document.body 
}).done(function() { 
  $( this ).addClass( "done" ); 
});