"Portals" were invented to concentrate Web traffic, mostly in order to sell more advertising space, although some have nobler goals. Concentrating traffic is counter to the essence of the Web, which is to enable peer to peer communication to avoid scalability bottlenecks. But there are by now so many portals, that instead of concentrating traffic, they help to distribute it.
Take an example: if you want information about the agenda of your local theatre, you could go to the theatre's own site. But there are probably at least half a dozen other sites that also carry that agenda, thus reducing the load on the theatre's server.
Unfortunately, all those sites have different interfaces and many hide the information in completely inadequate mark-up, as if the Web wasn't made to be read by computers. Ease of use is apparently not a priority for many of those portals, but that is a different discussion.Bert Bos <bert at phonk.net>