There are different types of websites based on the audience you are trying to reach. The three standard types include:
Essentially, all websites are portals by their very nature. In each case, information, data and sometimes applications are pulled together and made available in a central website - or portal. They may not be built on "portal technology", but they are portals none the less.
So if all websites are portals, then why don't we just call them that? I think the term generally causes confusion and concern among people. Most times, when the word portal is mentioned, people automatically assume a product and spending lots of money on licenses, hardware, and software. They don't seem to be able to look past the technology to the concept itself. Which is disappointing because if we think in terms of technology then I think portal is a fad (a long running one - but a fad just the same).
Instead, let's look at a portal as a concept and see the longevity it has. Because, really, all websites are portals by their very nature.