html - Why AJAX over iFrames?

Question

I am relatively new programmer, talking with a partner he told me, that before AJAX, he used a iframe to send data and change the content(obviously with help of JavaScript).

I understood that both are similar techniques, but i didn't find a article to describe their characteristic,

what are advantages of AJAX over Iframe ?

EDIT i didnt find any explanation of the technique, but my partner told me he post the data trough a hidden iframe and submit the iframe, sound like just the iframe have to be refreshed, but i never did that

Answer 1

1. One advantage AJAX has is being able to read the state/status of the request. You also have access to page headers, which you don't with Iframes.
2. Ajax can handle multiple asynch requests. It's a little trickier with Iframes as you need to create an Iframe per request (and keep track of all of them to delete them later) instead of recycling the same one.
3. Existing libraries are full of AJAX goodness and there is a larger community support base.