1.1. What Is RJS?

Ajax is a technology that allows a more desktop-like, interactive user experience to happen in the web browser. Basically, Ajax allows the browser to make remote requests in the background. These requests update the current page without reloading. Ruby on Rails has excellent support for Ajax baked right into the framework. Remote JavaScript (RJS) templates build upon the Ajax support offered by Rails 1.0, but go one step further, by allowing you to easily update multiple page elements.

RJS templates are a powerful new addition to Rails 1.1. Unlike other Rails templates, which are rendered and sent to the browser, RJS templates are used to update pages that have already been rendered.