What is WebSphere Portal?

WebSphere Portal is a framework--including a runtime server, services, tools, and many other features--that you can use to integrate your enterprise into a single, customizable interface called a portal (a website). An enterprise portal combines components, applications, processes, and content from a wide variety of sources into a unified presentation, which your users can access from a wide variety of devices.
You can customize the portal based on user or job roles, security needs, device settings, personal preferences, and administrative settings. You can also define workflows to support your business processes. You can manage your portal's content using IBM's Web Content Management, which is integrated with WebSphere Portal. Figure 1 shows an example company portal
A portal can be best described as a web site that acts as a "point of entry" or a gate to a larger system. While it seems pretty difficult to define a portal in the strictest sense, these are some of the common features of portals:
Content aggregation:
Portals tend to aggregate content from multiple, disparate sources and provide one unified view of the same.
Personalization:
This refers to the ability of the portal to tailor the content/services that it offers according to the user of the portal.
Search:
Most if not all portals, offer some form of searching of it's content and sometimes even content from external sources.
Single Sign On:
Allows users to authenticate once to the portal and thereby allows access to many other systems without the need for re authentication.