jQuery AJAX
AJAX = Asynchronous JavaScript and XML. AJAX is the art of exchanging data with a server, and updating parts of a web page - without reloading the whole page.
AJAX load() Method: The load() method loads data from a server and puts the returned data into the selected element.
$("#div1").load("demo_test.txt");
$("#div1").load("demo_test.txt #p1");