html or php redirect

on this website http://hauntedwisconsin.com/events/list/ is a menu - sort by zip or address, filter by type, when a visitor inputs a city the php in the box below changes and displays the information (in the events list below in the center of the page) and if a visitor picks a type of event the php in the events list changes below. IS this totally a html5 css3 function using the object redirect? or is it a function of php that makes this work? I would like to use this on countyfairgrounds.net but do not know how to implment this Can you help me?

I don't know the differences among the web address ending with html, org or php .

Thats Ajax (http://en.wikipedia.org/wiki/Ajax_%28programming%29)...where the browser send a request in the background to a server-side script with what you entered. Then the script searches the database and returns info to the client side Javascript which then refreshes the area content with the new content.

Jquery (http://api.jquery.com/jQuery.ajax/) has an easy way to implement it that multi-browser.