The JSR 168 specification aims at defining porlets that can be used by any JSR168 portlet container also called portals. There are different portals out there with commercial and non-commercial licences. In this chapter we will briefly describe such portlets but for more details you should read the specifications available on the web.
As of today, JBoss portal is fully JSR168 1.0 compliant, that means that any JSR168 portlet will behave as it should inside the portal.
What is really important to know about such portlets is that when a page is displayed it is divided into two distincts parts, an action part on one portlet followed by rendering parts for every porlets displayed on a page. A portal just aggregates all the chunks of HTML rendered by the different portlets of a page.
Before we even talk about portlets, let's talk about the container called portal.
A portal is basically a web application in which modules can be easily added or removed. We call those modules 'portlets'. A module can be as complex as a forum, a news management system or as simple as a text or text with images with no possible interaction.
On a single web page different portlets can appear at the same time.
A portal can be seen as pages with different areas and inside areas, different windows and each window having one portlet.