In this second part of a two-part series on the ins and outs of iframes, we will explore more uses for iframes. The ones we will discuss fall into the broad category of remote scripting, or remote procedure calls (RPC). You won't find any sophisticated code in this article, but we will do quite a bit with just plain HTML tags and some basic PHP.
To understand remote scripting, we should first consider how traditional web pages without remote scripting communicate with each other. When you click a link or submit a form on the first page, the second, also known as the "target page" to which the link or form points, loads into the browser, entirely replacing the first page. You see this process as your browser reloads. It takes some amount of time -- a small amount, granted, but enough to make some people impatient.
With remote scripting, the first page remains loaded in the browser while it sends information to the target page. The target page then returns a response to the first page, which causes a dynamic change while the page remains loaded. In other words, a web page communicates with another web page or script by sending or receiving data or both, while the page is still loaded in the browser.
If this is confusing to you, do not worry. It will become clear as we talk about some examples.