Officially this is a meaningless buzzword promoted by IBM (International Business Machines).
Portals are some sort of Servlet but IBM
incapable of explaining how they differ from ordinary Servlets. Some speculate they are used to present a webpage with
many services on it such as a search engine and news that come from diverse sources.
The user is able to dynamically configure the contents and layout of the page much
like Netscape home pages. They might also be simply a way of hosting command line
utilities in a platform-independent way.