What is a Portal?

The idea of a Portal is to collect information from different sources and create a single point of access to information - a library of categorized and personalized content. A portal also provides other valuable functions such as security, search, and workflow.

A Portal is a web application focused on:

Creating dynamic website	:	User oriented and extreamly dynamic fragments.
Page-centric approach	:	Each page hosts presentation layer apps Portlets Apps (wrapping using bridge framework) Gadgets (based on XML and JavaScript)
Aggregation of contents	:	Aggregation is the process of integrating content from different sources within a Webpage.
Enterprise Services	:	Authentication Authorization Personalization Export/Import APIs for integrations Single sign-on

Portal Architecture Explained:

The portal Web application processes the client request. Retrieves the portlets on the user's current page. Calls the portlet container to retrieve each portlet's content. The portlet container provides the runtime environment for the portlets and calls the portlets via the Portlet API. The portlet container is called from the portal via the Portlet Invoker API. The container retrieves information about the portal using the Portlet Provider SPI (Service Provider Interface).