In simple terms, a portal is a web "supersite" with a collection of links to popular web services on the Internet. A kind of "doorway" into the Internet. The site provides a variety of services including directories, online shopping, discussion groups, Web searching, channels (small windows within a page that are dynamically updated and determined by the user) and links to other sites. Typically a university home page will have many static links while a portal will allow the user to select certain links and possibly provide links to access secured data for that particular user. The links on a portal will be dynamically created for each user rather than static for the entire population. The host of a portal can arrange to "push" certain links onto your page while the user of a portal can specify which links they will "pull" to their portal.

Although the term "portal" was initially used to refer to general-purpose sites, it is increasingly being used to refer to vertical market sites that offer the same services, but only to a particular industry such as banking, insurance or computers. America Online was one of the first to develop the portal idea.

These services are usually provided for free in the hope that users will make the site their default home page or at least visit it often. Most portals on the Internet exist to increase hits on their sites and generate advertising income for their owners, while others may be focused on a specific group of users. Many sites have tried to make their portals personal by assigning a user ID and password, and might even place a cookie* (electronic cookie, that is) on the users' machine to keep track of information that the user has specified, such as stock prices, weather forecasts, sports scores, reminders of upcoming scheduled events. Some even allow the user to define the look of the portal by changing the colors and backgrounds.

Many people will debate which links should be pushed onto a page and whether the user should be given the rights to remove links that are pushed to them. Another question is whether or not a user should be allowed to add pull links that are of not in the hosts best interest for their portal to display. This brings up many familiar questions regarding the Internet about whether or not to regulate access and who will determine the content that is not appropriate.

There are five (5) basic types of portals: Customized Personalized Adaptive Desktop (CPAD) portals, Horizontal portals, Vertical Niche portals, Corporate and Enterprise portals. Refer to Table 1 for an example of each type of portal.

CPAD can be created by software and is displayed when users authenticate themselves. A CPAD can be customized for different hardware to provide the maximum efficiency. It can also be personalized for different alerts and notices. The user has the option and ability to format its appearance to their liking; they can change the colors, backgrounds, and available links. This information can also be available to be edited and removed at a later time. The portal can also be adapted to the specific user's needs. It could remind them of reviews and other meetings, and then provide access to the files. A CPAD portal could replace the users knowledge of an operating system by providing access to everything with the click of a mouse.

A horizontal portal or mega portal allows the user many of the same privileges of a CPAD, however, it does not provide access to files outside of what that web site holds. Personalization of the portal is allowed and is often saved by the web site placing a cookie* on the users machine.

A vertical-market Web site that provides information and services to a particular industry. A vertical niche portal will address a specific audience such as a golf group. It is the industry-specific equivalent of the general-purpose portal. This portal will only provide information about a certain topic and try to personalize the information to the user. A vertical niche portal will be structured according to industry standards such as the financial sector.

An enterprise portal would be used in a setting where there are many different roles and users involved such as a university. Personalization (the ability to set the backgrounds and overall look of the portal) and customization (the ability to allow the user to receive personal information about themselves) can be used to help the portal adapt to the users needs; authentication is required. The home page will be different but will be specific for the different users roles. An enterprise portal is similar to a CPAD in that a user can customize their portal as well as have access to change and add information to a university's database. According to the Delphi groups research 55 % of the Fortune 500 companies currently have a vertical niche portal currently working.

A corporate portal is an internal Web site (intranet) that provides proprietary, enterprise-wide information to employees as well as access to selected public Web sites and vertical-market Web sites (supplies, vendors). It includes a search engine for internal documents as well as the ability to customize the portal page for different user groups and individuals. It is the internal equivalent of the general-purpose portal. A corporate portal that enables users to query and produce reports on enterprise-wide databases is called a business intelligence portal. The term was coined by Information Advantage, makers of MyEureka software.

*HTTP Cookie - A packet of information sent by an HTTP server to a World Wide Web browser and then sent back by the browser each time it accesses that server. Typically this is used to authenticate or identify a registered user of a web site without requiring them to sign in again every time they access that site. Other uses are, maintaining a "shopping basket" of goods you have selected to purchase during a session at a site, site personalization (presenting different pages to different users), tracking a particular user's access to a site.