Some site owners who have big amount of information posted that is being updated frequently may consider adding RSS functionality to their web sites to allow visitors to subscribe to the resource and see all the new information as it appears.
This technology is quite popular today and there are many ways on how it can be implemented and used.
Concerning the RSS basics, on one side there is RSS feed that is created on a web site and on the other is RSS reader, some program or on-line service that retrieves information from the desired feeds according to some specified schedule.
The web-part of the RSS feed is actually quite simple and consists of a specific .xml file (rss.xml) that defines your web site RSS channel and collects all the recent updates in a form that RSS reader (RSS agregator) can understand.
<?xml version="1.0" encoding="ISO-8859-1" ?>
<title>Web site news page</title>
<description>All the recent news right here</description>
<description>Here you can find the latest news</description>
<title>Another latest news</title>
<description>Here you can find the other latest news</description>
A link to such RSS container file can then be published on your web site to be seens by your clients.
The file itself can be created either manually as you publish updates to your web site or automatically by your web site scripts or engine that dynamically builds your web pages.
Today there are many different scripting libraries (for PHP, ASP and ColdFusion), CMS and blogging applications that can help you in implementing RSS functionality on your portal, so it is more a questions of preference for your site developer to chose one of the implementation methods.
The additional information on RSS technology and its methods can be found on a different Internet sites, like this one.