When you start exploring the Web, you will realise just how vast it is, and most of it is of no interest to you at all. Finding what you want on the Web is very difficult -- even with the help of search engines, and link collections. It would be nice if someone or something could do all the donkey work for you, and just let you look at the pages that you really need to see. This will probably take some of the fun out of exploring the Web, but those of us who use it more for serious use will find such things very useful.
Intelligent Agents are the name given to a new kind of software that is designed to hunt out the information that you want. They do this by browsing the Web whilst you are doing other things, and they build up a page of links to the pages that they think you are likely to be interested in. As time goes by, you train your agent (it spies on what you really look at) to become better at hunting out the pages you really want.