Atlas architecture

I have written a simple form and it is now Ajaxed up and everything is working
fine. I wanted to ask why  when you invoke a method in an Ajax application the
Page events (page_load, render etc_ get fired? Even when i have partial
rendering set to true and its just a small section of the page that is being
updated?

thanks

Ajax / Atlas is an async interpretation layer.  It dosent change the way
codebehind or event heirachy works, just the way your page relates to it.  A
Page_Load still fires, because when they developed Ajax / Atlas, they determined
that it'd probably be important that one still fire.  

What's getting updated is whatever is inside your update panel.  It querys the
server for new data, and loads it asyncronously into the page, just like
changing a controls value in Javascript would do  (asyncronious javascript and
xml, ajax).

It performs the rendering on the client instead of the server.

hello.

well, that is what you get when you use pagemethods or updatepanels. this
doesn't happen when you use web services (which might be the way to go in most
scenarios, though most people end up using updatepanels).