The woman on my answering machine sounded incredulous, as if she had heard aliens were landing on the Mall. She had read that The Washington Post was turning its Web site into a regional portal and felt the story had omitted a basic fact:

What, pray tell, is a "portal"?

Good question, one that cuts to the Internet's chronic identity crisis. Readers ask it all the time, and the question gets harder to answer because the mission of many Web sites grows fuzzier as the global network expands. I usually reply that a portal--which literally means a doorway, entrance or gateway--is a launching pad for the Web, a guide like Yahoo that helps direct people to resources scattered online.

The truth is that portals are more complex than that. Anyone who offers a simple definition is glossing over the Net's amorphous, dynamic nature.

It's safe to say that the Internet industry has gone portal-mad, hanging the label on just about every site on the World Wide Web. Many entrepreneurs tout their sites as portals in an attempt to ride on the coattails of the Web's most heavily trafficked sites, those all-purpose portals such as Lycos and Go.

Basically, you should think of portals as electronic dashboards that help people navigate the Net much as scheduling billboards help guide travelers through airports. Portals act as menus or tables of contents.

In addition to the true general portals, there are thousands of specialty, or "vertical," portals, such as Time Warner's impending site and for African Americans, aimed at a single topic or audience. There are corporate portals, too, such as the internal Web sites that Yahoo said last week it and Hewlett-Packard Co. would customize and sell to big companies.

Then there are geographic portals. The nation's newspapers and other local media outlets have become portal wanna-bes in their mad dash to build "regional portals," collections of resources specific to the geographic areas they serve., like many newspaper sites, is planning to add useful features such as e-mail and Web searching. In part, the idea is to reorganize the existing site layouts to highlight shopping and local services, not just the news.

"Microportal" is an even more confusing moniker, often used to describe Internet guides that exist outside traditional Web browsers. AltaVista, for example, offered free Internet access last week to people who agree to accept an advertising spot on their screens connected to their new desktop microportal. AltaVista's microportal is a rectangular window that displays news headlines, sports scores and stock quotes, even when people are not surfing the Web. In testing it, I found the free access simple to set up, but the microportal so ridiculously tiny that it was like trying to read Yahoo's menu on a postage stamp.

All of which raises the question: What is a portal? Even the folks building the leading ones give different answers.

While on the surface portals may seem like simple electronic channel guides, underneath they tend to be complex networks of interactive services. Mega-sites such as Microsoft's are too dynamic to fit neatly under one label; they change constantly in response to how people are using them. The major portals all have people who do nothing but monitor search logs, studying what surfers are looking for elsewhere on the Web and then, like amoebas, trying to swallow or copy the best features of those sites to keep customers on their own electronic turf.

Therein lies the identity crisis. Major portals have become oxymorons, with built-in tension that puts them in conflict with their own identity. They started as Web indexes pointing outward, doorways through which surfers passed on their way somewhere else. Then they spent the past two years setting up a dizzying array of electronic stalls, shops, features and services to keep surfers longer so they could sell more advertising and collect more commissions on commercial transactions. In addition to free e-mail, chat and stock portfolios, portals have deep channels of services today that replicate the material on the vertical portals.

It's as if the doorway turned into a tunnel. Or as if Bloomingdale's stationed a directory in the main aisle of its housewares section so it could list all the contents over at Crate & Barrel--and charge Crate & Barrel for the promotion.

No wonder we get confused.

This tension between portals' indexing functions and their desire to offer the same services as the sites they index has led to a debate over how long the general portals can dominate cyberspace. Many analysts believe specialty portals will steadily increase in value, eroding revenue sources for general portals as Internet users bookmark their favorite sites and bypass the portals' directories. If that happens on a massive scale, the portals would have a harder time collecting referral and advertising fees from other Web sites.

Some analysts also think the portals' tool kits--chat, e-mail, instant messaging, news headlines--are becoming indistinguishable, making it easier for top-quality services offered by the specialty sites to shine in contrast.

But that seems simplistic, akin to saying stores such as Circuit City and Toy-R-Us will destroy all department stores, rather than simply force the competitive ones to change. People who can't be bothered with Wal-Mart may never use Yahoo either, preferring to go to Internet category killers such as But I am convinced there will always be folks who appreciate all-in-one surfing just as there will always be those who love one-stop shopping.

That's not to say some of today's prime portal real estate won't turn into ghost towns tomorrow. The Internet is a lot like quicksand--and it is easy to picture portals as holes that can close as quickly as they opened, swallowing all the dreams and dollars that people dropped into them.

Leslie Walker's e-mail address is