Building a portal involves integrating diverse technology applications & content aggregation and delivery to be delivered via a uniform easy to use browser based user interface to the user. These services are in turn delivered by multiple applications which are not usually available from the same stable. Issues like user management, single sign-on and user synchronization, as well as maintenance of user and application states across these applications become vital.
Portals are Websites or services that offer a broad array of resources and services, such as e-mail, forums, search engines, content and on-line shopping malls. The first Web portals were online services, such as America Online (AOL), Yahoo! that provided access to the Web, but by now most of the traditional search engines have transformed themselves into Web portals becoming an online interaction point for virtual communities.